Sample records for polyethylene pe films
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Polyethylene-Carbon Nanotube Composite Film Deposited by Cold Spray Technique
NASA Astrophysics Data System (ADS)
Ata, Nobuhisa; Ohtake, Naoto; Akasaka, Hiroki
2017-10-01
Carbon nanotubes (CNTs) are high-performance materials because of their superior electrical conductivity, thermal conductivity, and self-lubrication, and they have been studied for application to polymer composite materials as fillers. However, the methods of fabricating polymer composites with CNTs, such as injection molding, are too complicated for industrial applications. We propose a simple cold spray (CS) technique to obtain a polymer composite of polyethylene (PE) and CNTs. The composite films were deposited by CS on polypropylene and nano-porous structured aluminum substrates. The maximum thickness of the composite film was approximately 1 mm. Peaks at G and D bands were observed in the Raman spectra of the films. Scanning electron microscopy images of the film surface revealed that PE particles were melted by the acceleration gas and CNTs were attached with melted PE. The PE particles solidified after contact with the substrate. These results indicate that PE-CNT composite films were successfully deposited on polypropylene and nano-porous structured aluminum substrates by CS.
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Surface modification of a polyethylene film for anticoagulant and anti-microbial catheter
Zheng, Yingying; Miao, Jianjun; Zhang, Fuming; Cai, Chao; Koh, Amanda; Simmons, Trevor J.; Mousa, Shaker A.; Linhardt, Robert J.
2016-01-01
A functional anticoagulant and anti-bacterial coating for polyethylene (PE) films is described. The stepwise preparation of this nanocomposite surface coating involves O2 plasma etching of PE film, carbodiimide coupling of cysteamine to the etched PE film, binding of Ag to sulfhydryl groups of cysteamine, and assembly of heparin capped AgNPs on the PE film. The nanocomposite film and its components were characterized by 1H-nuclear magnetic resonance spectroscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and field emission-scanning electron microscopy. The resulting PE films demonstrate anticoagulant activity using a hemoglobin whole blood clotting assay, and anti-bacterial activity against Bacillus cereus 3551 (Gram-positive) and Escherichia coli BL21 (Gram-negative) bacteria. The hydrophilicity of the heparin coated PE was determined by contact angle measurements; and the stability of the nanocomposite film, with respect to Ag leaching, was assessed by atomic absorption spectroscopy. PMID:26900340
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Sabetzadeh, Maryam; Bagheri, Rouhollah; Masoomi, Mahmood
2016-05-05
The aim of this work is to study effect of nanoclay (Cloisite(®)15A) on morphology and properties of low-density polyethylene/linear low-density polyethylene/thermoplastic starch (LDPE/LLDPE/TPS) blend films. LDPE/LLDPE blend (70/30wt/wt) containing 15wt.% TPS in the presence of PE-grafted maleic anhydride (PE-g-MA, 3wt.%) with 1, 3 and 5phr of nanoclay are compounded in a twin-screw extruder and then film blown using a blowing machine. Nanocomposites with intercalated structures are obtained, based on the X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies. However, some exfoliated single platelets in the samples are also observable. Scanning electron microscopic (SEM) images confirm the ability of both exfoliated nanoclay and PE-g-MA to reduce the size of TPS domains and deform their particles within the PE matrices. As the nanoclay content increases from 1 to 5phr, the tensile strength, tear resistance and impact strength of the films increase, whereas a slight decrease in the elongation at break is observed. The film samples with 5phr nanoclay possess the required packaging properties, as specified by ASTM D4635. These films provide desired optical transparency and surface roughness which are more attractive for packaging applications. Copyright © 2016. Published by Elsevier Ltd.
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Preparation of chitosan-coated polyethylene packaging films by DBD plasma treatment.
Theapsak, Siriporn; Watthanaphanit, Anyarat; Rujiravanit, Ratana
2012-05-01
Polyethylene (PE) packaging films were coated with chitosan in order to introduce the antibacterial activity to the films. To augment the interaction between the two polymers, we modified the surfaces of the PE films by dielectric barrier discharge (DBD) plasma before chitosan coating. After that the plasma-treated PE films were immersed in chitosan acetate solutions with different concentrations of chitosan. The optimum plasma treatment time was 10 s as determined from contact angle measurement. Effect of the plasma treatment on the surface roughness of the PE films was investigated by atomic force microscope (AFM) while the occurrence of polar functional groups was observed by X-ray photoelectron spectroscope (XPS) and Fourier transformed infrared spectroscope (FTIR). It was found that the surface roughness as well as the occurrence of oxygen-containing functional groups (i.e., C═O, C-O, and -OH) of the plasma-treated PE films increased from those of the untreated one, indicating that the DBD plasma enhanced hydrophilicity of the PE films. The amounts of chitosan coated on the PE films were determined after washing the coated films in water for several number of washing cycles prior to detection of the chitosan content by the Kjaldahl method. The amounts of chitosan coated on the PE films were constant after washing for three times and the chitosan-coated PE films exhibited appreciable antibacterial activity against Escherichia coli and Staphylococcus aureus. Hence, the obtained chitosan-coated PE films could be a promising candidate for antibacterial food packaging.
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Syranidou, Evdokia; Karkanorachaki, Katerina; Amorotti, Filippo; Repouskou, Eftychia; Kroll, Kevin; Kolvenbach, Boris; Corvini, Philippe F-X; Fava, Fabio
2017-01-01
This study investigated the potential of bacterial-mediated polyethylene (PE) degradation in a two-phase microcosm experiment. During phase I, naturally weathered PE films were incubated for 6 months with the indigenous marine community alone as well as bioaugmented with strains able to grow in minimal medium with linear low-density polyethylene (LLDPE) as the sole carbon source. At the end of phase I the developed biofilm was harvested and re-inoculated with naturally weathered PE films. Bacteria from both treatments were able to establish an active population on the PE surfaces as the biofilm community developed in a time dependent way. Moreover, a convergence in the composition of these communities was observed towards an efficient PE degrading microbial network, comprising of indigenous species. In acclimated communities, genera affiliated with synthetic (PE) and natural (cellulose) polymer degraders as well as hydrocarbon degrading bacteria were enriched. The acclimated consortia (indigenous and bioaugmented) reduced more efficiently the weight of PE films in comparison to non-acclimated bacteria. The SEM images revealed a dense and compact biofilm layer and signs of bio-erosion on the surface of the films. Rheological results suggest that the polymers after microbial treatment had wider molecular mass distribution and a marginally smaller average molar mass suggesting biodegradation as opposed to abiotic degradation. Modifications on the surface chemistry were observed throughout phase II while the FTIR profiles of microbially treated films at month 6 were similar to the profiles of virgin PE. Taking into account the results, we can suggest that the tailored indigenous marine community represents an efficient consortium for degrading weathered PE plastics. PMID:28841722
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Sabetzadeh, Maryam; Bagheri, Rouhollah; Masoomi, Mahmood
2015-03-30
In this work, low-density polyethylene/linear low-density polyethylene/thermoplastic starch (LDPE/LLDPE/TPS) films are prepared with the aim of obtaining environmentally friendly materials containing high TPS content with required packaging properties. Blending of LDPE/LLDPE (70/30 wt/wt) with 5-20 wt% of TPS and 3 wt% of PE-grafted maleic anhydride (PE-g-MA) is performed in a twin-screw extruder, followed by the blowing process. Differential scanning calorimetric results indicate starch has more pronounced effect on crystallization of LLDPE than LDPE. Scanning electron micrograph shows a fairly good dispersion of TPS in PE matrices. Fourier transfer infrared spectra confirm compatibility between polymers using PE-g-MA as the compatibilizer. Storage modulus, loss modulus and complex viscosity increase with incorporation of starch. Tensile strength and elongation-at-break decrease from 18 to 10.5 MPa and 340 to 200%, respectively when TPS increases from 5 to 20%. However, the required mechanical properties for packaging applications are attained when 15 wt% starch is added, as specified in ASTM D4635. Finally 12% increase in water uptake is achieved with inclusion of 15 wt% starch. Copyright © 2014 Elsevier Ltd. All rights reserved.
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NASA Astrophysics Data System (ADS)
Martínez-Romo, A.; González Mota, R.; Bernal, J. J. Soto; Frausto Reyes, C.; Rosales Candelas, I.
2015-01-01
One of the most widely used plastics in the world is the High density polyethylene (HDPE), it is a stable material due to its carbon-carbon bonds, causing their slow degradation; which is why we are looking for alternative ways to accelerate the degradation process of this polymer. An alternative is the addition of oxidized groups in its molecular structure, which results in the development of polymers susceptible to biodegradation (PE-BIO). In this paper, HDPE and PE-BIO films were exposed to UV-B radiation (320-280 nm) at different exposure times, 0-60 days. The effects of UV radiation in samples of HDPE and PE-BIO were characterized using infrared spectroscopy with attenuated total reflectance (ATR). The results show that the exposed materials undergo changes in their molecular structure, due to the infrared bands formed which corresponds to the photo-oxidation of HDPE and PE films when submitted to UV-B radiation.
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Effects of Gravity on Ignition and Combustion Characteristics of Externally Heated Polyethylene Film
NASA Astrophysics Data System (ADS)
Ikeda, Mitsumasa
2018-04-01
The objective of this research is to investigate the effects of gravity on the ignition and the combustion characteristics of the Polyethylene (PE) film by outer heating. Combustion experiments of PE film were carried out in a normal gravity field and the microgravity field. In the microgravity experiments, it was carried out in 50 m-class drop facility. Here it can be realized 10- 4G microgravity field in about 2.5-3.0 second. The PE film is heated by the inserted high-temperature chamber. In the experiments, the PE was used film type. The chamber temperature was fixed at 900 K and 1000 K. In the case of microgravity field, the ignition delay period has become about 50 percent shorter than that in the case of the normal gravitational field. In the normal gravity field, since the PE surface layer is cooled by natural convection, the ignition delay period is considered to be longer than that in the microgravity field. The combustion time in the normal gravity was about 0.8 sec. In the microgravity field, the combustion time was more than 2 sec, and it could not be measured during the free fall period.
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Effect of degrading yellow oxo-biodegradable low-density polyethylene films to water quality
NASA Astrophysics Data System (ADS)
Requejo, B. A.; Pajarito, B. B.
2017-05-01
Polyethylene (PE) contributes largely to plastic wastes that are disposed in aquatic environment as a consequence of its widespread use. In this study, yellow oxo-biodegradable low-density PE films were immersed in deionized water at 50°C for 49 days. Indicators of water quality: pH, oxidation-reduction potential, turbidity, and total dissolved solids (TDS), were monitored at regular intervals. It was observed that pH initially rises and then slowly decreases with time, oxidation-reduction potential decreases then slowly increases with time, turbidity rises above the control at varied rates, and TDS increases abruptly and rises at a hindered rate. Moreover, the films potentially leach out lead chromate. The results imply that degrading oxo-biodegradable LDPE films results to significant reduction of water quality.
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NASA Astrophysics Data System (ADS)
Ching, Yern Chee; Yaacob, Iskandar Idris
2011-06-01
Polyethylene (PE) film was coated with polyurethane/nanosilica composite layer using rod Mayer process. The polyurethane/nanosilica system was prepared by dispersing nanosilica powder into solvent borne polyurethane (PU) binder under vigorous stirring. The silica nanoparticle used has an average diameter of 16 nm, and their weight fraction were varied from 0 % to 14 %. Two different thicknesses of the PU/nanosilica coating layer were fabricated which were about 4 μm and 8 μm. The structure and thermal mechanical features of the nanocomposite coated PE film were characterized by scanning electron microscope (SEM), dynamic mechanical analyzer (DMA), thermogravimetric analyzer (TGA) as well as tensile tests. The results showed that thin layer coating of the PU/nanosilica composite reduced tensile strength of PE substrate slightly. However, the nanocomposite coating of up to 8 μm reduced the elongation % of PE substrate significantly. PU/nanosilica composite coating layer increased the tensile modulus and stiffness of PE substrate. There was no influence of the PU/nanosilica composite coating to the thermal degradation rate of PE film.
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Bio-based biodegradable film to replace the standard polyethylene cover for silage conservation.
Borreani, Giorgio; Tabacco, Ernesto
2015-01-01
The research was aimed at studying whether the polyethylene (PE) film currently used to cover maize silage could be replaced with bio-based biodegradable films, and at determining the effects on the fermentative and microbiological quality of the resulting silages in laboratory silo conditions. Biodegradable plastic film made in 2 different formulations, MB1 and MB2, was compared with a conventional 120-μm-thick PE film. A whole maize crop was chopped; ensiled in MB1, MB2, and PE plastic bags, 12.5kg of fresh weight per bag; and opened after 170d of conservation. At silo opening, the microbial and fermentative quality of the silage was analyzed in the uppermost layer (0 to 50mm from the surface) and in the whole mass of the silo. All the silages were well fermented with little differences in fermentative quality between the treatments, although differences in the mold count and aerobic stability were observed in trial 1 for the MB1 silage. These results have shown the possibility of successfully developing a biodegradable cover for silage for up to 6mo after ensiling. The MB2 film allowed a good silage quality to be obtained even in the uppermost part of the silage close to the plastic film up to 170d of conservation, with similar results to those obtained with the PE film. The promising results of this experiment indicate that the development of new degradable materials to cover silage till 6mo after ensiling could be possible. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
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Ramos, Laura; Berenstein, Giselle; Hughes, Enrique A; Zalts, Anita; Montserrat, Javier M
2015-08-01
Horticulture makes intensive use of soil and extensive use of polyethylene (PE) sheeting and pesticides, producing an environment where the dynamics between soil and plastics can affect pesticide fate. We have determined that the presence of plastic residues in the horticultural soil of small production units equals 10% of the soil area, being meso and macro-sections the predominant fragment sizes. All soil samples were taken from different plots located in Cuartel V, Moreno district, in the suburbs of Buenos Aires city, Argentina. Laboratory experiments were conducted to see the relations among pesticide, soil and PE film. Endosulfan recovery from LDPE films (25μm and 100μm) was studied, observing evidence that indicated migration to the inside of the plastic matrix. To further analyze the dynamics of pesticide migration to soil and atmosphere, experiments using chlorpyrifos, procymidone and trifluralin were performed in soil-plastic-atmosphere microenvironments, showing that up to 24h significant amounts of pesticides moved away from the PE film. To determine whether PE residues could act as potential pesticide collector in soil, column elution experiments were done using chlorpyrifos, procymidone and trifluralin. Results showed an important pesticide accumulation in the mulch film (584μg-2284μg pesticide/g plastic) compared to soil (13μg-32μg pesticide/g soil). Finally, chemical and photochemical degradation of deltamethrin adsorbed in PE film was studied, finding a protective effect on hydrolysis but no protective effect on photodegradation. We believe that a deeper understanding of the dynamics among soil, plastic and pesticides in horticultural productive systems may contribute to alert for the implications of PE use for plastic sheeting. Copyright © 2015 Elsevier B.V. All rights reserved.
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Oil-Impregnated Polyethylene Films
NASA Astrophysics Data System (ADS)
Mukherjee, Ranit; Habibi, Mohammad; Rashed, Ziad; Berbert, Otacilio; Shi, Shawn; Boreyko, Jonathan
2017-11-01
Slippery liquid-infused porous surfaces (SLIPS) minimize the contact angle hysteresis of a wide range of liquids and aqueous food products. Although hydrophobic polymers are often used as the porous substrate for SLIPS, the choice of polymer has been limited to silicone-based or fluorine-based materials. Hydrocarbon-based polymers, such as polyethylene, are cost effective and widely used in food packaging applications where SLIPS would be highly desirable. However, to date there have been no reports on using polyethylene as a SLIPS substrate, as it is considered highly impermeable. Here, we show that thin films of low-density polyethylene can be stably impregnated with carbon-based oils without requiring any surface modification. Wicking tests reveal that oils with sufficient chemical compatibility follow Washburn's equation. The nanometric effective pore size of the polyethylene does result in a very low wicking speed, but by using micro-thin films and a drawdown coater, impregnation can still be completed in under one second. The oil-impregnated polyethylene films promoted ultra-slippery behavior for water, ketchup, and yogurt while remaining durable even after being submerged in ketchup for over one month. This work was supported by Bemis North America (AT-23981).
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Development of an iron chelating polyethylene film for active packaging applications.
Tian, Fang; Decker, Eric A; Goddard, Julie M
2012-02-29
Metal-promoted oxidation reactions are a major cause of food quality deterioration. Active packaging offers novel approaches to controlling such oxidation for the purpose of extending shelf life. Herein, we report modification of the surface of polyethylene (PE) films to possess metal chelating activity. Metal chelating carboxylic acids were introduced to the film surface using cross-linking agents [polyethylenimine (PEI) or ethylenediamine (ED)] to increase the number of available carboxylic acids. ATR-FTIR, contact angle, dye assay, and iron chelating assay were used to characterize changes in surface chemistry after each functionalization step. The chelator poly(acrylic acid) (PAA) was attached to the surface at a density of 9.12 ± 0.71 nmol carboxyl groups/cm², and exhibited an iron chelating activity. The results indicate that PAA-modified PE films might have a higher affinity to Fe³⁺ than Fe²⁺ with the optimum binding pH at 5.0. Such inexpensive active packaging materials are promising in food industry for the preservation of liquid and semiliquid food products and have application in heavy metal chelation therapy for biomedical materials as well.
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Cinelli, Patrizia; Schmid, Markus; Bugnicourt, Elodie; Coltelli, Maria Beatrice; Lazzeri, Andrea
2016-01-01
Multilayer plastic films provide a range of properties, which cannot be obtained from monolayer films but, at present, their recyclability is an open issue and should be improved. Research to date has shown the possibility of using whey protein as a layer material with the property of acting as an excellent barrier against oxygen and moisture, replacing petrochemical non-recyclable materials. The innovative approach of the present research was to achieve the recyclability of the substrate films by separating them, with a simple process compatible with industrial procedures, in order to promote recycling processes leading to obtain high value products that will beneficially impact the packaging and food industries. Hence, polyethyleneterephthalate (PET)/polyethylene (PE) multi-layer film was prepared based on PET coated with a whey protein layer, and then the previous structure was laminated with PE. Whey proteins, constituting the coating, can be degraded by enzymes so that the coating films can be washed off from the plastic substrate layer. Enzyme types, dosage, time, and temperature optima, which are compatible with procedures adopted in industrial waste recycling, were determined for a highly-efficient process. The washing of samples based on PET/whey and PET/whey/PE were efficient when performed with enzymatic detergent containing protease enzymes, as an alternative to conventional detergents used in recycling facilities. Different types of enzymatic detergents tested presented positive results in removing the protein layer from the PET substrate and from the PET/whey/PE multilayer films at room temperature. These results attested to the possibility of organizing the pre-treatment of the whey-based multilayer film by washing with different available commercial enzymatic detergents in order to separate PET and PE, thus allowing a better recycling of the two different polymers. Mechanical properties of the plastic substrate, such as stress at yield, stress and
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Cinelli, Patrizia; Schmid, Markus; Bugnicourt, Elodie; Coltelli, Maria Beatrice; Lazzeri, Andrea
2016-06-14
Multilayer plastic films provide a range of properties, which cannot be obtained from monolayer films but, at present, their recyclability is an open issue and should be improved. Research to date has shown the possibility of using whey protein as a layer material with the property of acting as an excellent barrier against oxygen and moisture, replacing petrochemical non-recyclable materials. The innovative approach of the present research was to achieve the recyclability of the substrate films by separating them, with a simple process compatible with industrial procedures, in order to promote recycling processes leading to obtain high value products that will beneficially impact the packaging and food industries. Hence, polyethyleneterephthalate (PET)/polyethylene (PE) multi-layer film was prepared based on PET coated with a whey protein layer, and then the previous structure was laminated with PE. Whey proteins, constituting the coating, can be degraded by enzymes so that the coating films can be washed off from the plastic substrate layer. Enzyme types, dosage, time, and temperature optima, which are compatible with procedures adopted in industrial waste recycling, were determined for a highly-efficient process. The washing of samples based on PET/whey and PET/whey/PE were efficient when performed with enzymatic detergent containing protease enzymes, as an alternative to conventional detergents used in recycling facilities. Different types of enzymatic detergents tested presented positive results in removing the protein layer from the PET substrate and from the PET/whey/PE multilayer films at room temperature. These results attested to the possibility of organizing the pre-treatment of the whey-based multilayer film by washing with different available commercial enzymatic detergents in order to separate PET and PE, thus allowing a better recycling of the two different polymers. Mechanical properties of the plastic substrate, such as stress at yield, stress and
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Tarek, Abdussamad R; Rasco, Barbara A; Sablani, Shyam S
2016-06-01
Food safety is becoming an increasing concern in the United States. This study investigated the effects of ultraviolet-C (UV-C) light as a postpackaging bactericidal treatment on the quality of English cucumber packaged in polyethylene (PE) film. Escherichia coli k-12 was used as a surrogate microbe. The microbial growth and physical properties of packaged cucumbers were analyzed during a 28-d storage period at 5 °C. Inoculating packaged cucumbers treated at 23 °C for 6 min with UV-C (560 mJ/cm(2) ) resulted in a 1.60 log CFU/g reduction. However, this treatment had no significant effect (P > 0.05) on the water vapor transmission rate or oxygen transmission rate of the PE film. Results show that UV-C light treatment delayed the loss of firmness and yellowing of English cucumber up to 28 d at 5 °C. In addition, UV-C light treatment extended the shelf life of treated cucumber 1 wk longer compared to untreated cucumbers. Electron microscopy images indicate that UV-C light treatment influences the morphology of the E. coli k-12 cells. Findings demonstrate that treating cucumbers with UV-C light following packaging in PE film can reduce bacterial populations significantly and delay quality loss. This technology may also be effective for other similarly packaged fresh fruits and vegetables. © 2016 Institute of Food Technologists®
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Garrido-López, Alvaro; Esquiu, Vanesa; Tena, María Teresa
2006-08-18
A pressurized fluid extraction (PFE) and gas chromatography-flame ionization detection (GC-FID) method is proposed to determine the slip agents in polyethylene (PE) films. The study of PFE variables was performed using a fractional factorial design (FFD) for screening and a central composite design (CCD) for optimizing the main variables obtained from the Pareto charts. The variables that were studied include temperature, static time, percentage of cyclohexane and the number of extraction cycles. The final condition selected was pure isopropanol (two times) at 105 degrees C for 16min. The recovery of spiked oleamide and erucamide was around 100%. The repeatability of the method was between 9.6% for oleamide and 8% for erucamide, expressed as relative standard deviation. Finally, the method was applied to determine oleamide and erucamide in several polyethylene films and the results were statistically equal to those obtained by pyrolysis and gas-phase chemiluminescence (CL).
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76 FR 54791 - Polyethylene Terephthalate (PET) Film From Korea
Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-02
... Terephthalate (PET) Film From Korea Determination On the basis of the record \\1\\ developed in the subject five... order on polyethylene terephthalate (PET) film from Korea would not be likely to lead to continuation or... in USITC Publication 4254 (August 2011), entitled Polyethylene Terephthalate (PET) Film from Korea...
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NASA Technical Reports Server (NTRS)
Golub, Morton A.; Cormia, Robert D.
1989-01-01
The ESCA (electron spectroscopy for chemical analysis) spectra of films of poly(vinylidene fluoride) (PVDF), tetrafluoroethylene-ethylene copolymer (TFE/ET) and polyethylene (PE) exposed to atomic oxygen (O(P-3)), in or out of the glow of a radio-frequency O2 plasma, were compared. ESCA spectra of PE films exposed to (O(P-3)) in low Earth orbit (LEO) on the STS-8 Space Shuttle were also examined. Apart from O(P-3)-induced surface recession (etching), the various polymer films exhibited surface oxidation, which proceeded towards equilibrium saturation oxygen levels. The maximum surface oxygen uptakes for in-glow or out-of-glow exposures were in the order: PE greater than TFE/ET greater than PVDF; for PE itself, the oxygen uptakes were in the order: in glow greater than out of glow greater than LEO. Given prior ESCA data on poly(vinyl fluoride) and polytetrafluoroethylene films exposed to O(P-3), the extent of surface oxidation is seen to decrease regularly with increase in fluorine substitution in a family of ethylene-type polymers. (Keywords: ESCA; poly(vinylidene fluoride); tetrafluoroethylene ethylene copolymer; polyethylene; atomic oxygen; radio-frequency oxygen plasma; low Earth orbit)
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Kang, Sun-Chul; Kim, Min-Jeong; Park, In-Sik; Choi, Ung-Kyu
2008-03-01
This study was conducted to investigate the effect of modified atmosphere packaging (MAP) in combination with BN/PE film on the shelf life and quality of fresh-cut iceberg lettuce during cold storage. The total mesophilic population in the sample packed in BN/PE film under MAP conditions was dramatically reduced in comparison with that of PE film, PE film under MAP conditions, and BN/PE film. The O2 concentration in the BN/PE film under MAP conditions decreased slightly as the storage period progressed. The coloration of the iceberg lettuce progressed the slowest when it was packaged in BN/PE film under MAP conditions, followed by BN/PE film, PE film, and PE film under MAP conditions. The shelf life of fresh-cut iceberg lettuce packaged in the BN/PE film under MAP conditions was extended by more than 2 days at 10 degrees as compared with that of the BN/PE film in which the extension effect was more than 2 days longer than that of PE, PET, and OPP films.
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XPS analysis of PE and EVA samples irradiated at different γ-doses
NASA Astrophysics Data System (ADS)
Dorey, Samuel; Gaston, Fanny; Marque, Sylvain R. A.; Bortolotti, Benjamin; Dupuy, Nathalie
2018-01-01
The principal plastic materials used for the fluid contact and storage in the biopharmaceutical industry are mainly made up of semi-crystalline polymers, polyolefins, PVC, Siloxane and PET. The polyethylene (PE) and the polypropylene (PP) are often used as fluid contact in multi-layer materials like films. As one sterilisation way of single-use plastic devices used in medical and pharmaceutical fields can take place via γ-irradiation, the effect of sterilization on plastics must be investigated. The irradiation process leads to the production of radicals, which can generate changes in the polymer structure and on the polymer surface. It is well known that the presence of oxygen with free radicals precede the generation of peroxide species so called ROS (reactive oxygen species) which are highly reactive. The purpose of this work is to investigate the γ-rays impact on the surface of PE (polyethylene) and EVA (polyethylene vinyl alcohol) based films when ionized at different doses. X-ray Photoelectron Spectroscopy (XPS) was applied to determine the surface compositions of the polymers to highlight the different chemical moieties generated during the γ-irradiation process and to monitor the potential presence of the ROS.
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NASA Astrophysics Data System (ADS)
Sun, Jie; Qiu, Yiping
2015-05-01
Polyethylene (PE) films are treated using an atmospheric pressure plasma jet (APPJ) with He or He/O2 gas for different periods of time. The influence of gas type on the plasma-polymer interactions is studied. The surface contact angle of the PE film can be effectively lowered to 58° after 20 s of He/O2 plasma treatment and then remains almost unchanged for longer treatment durations, while, for He plasma treatment, the film surface contact angle drops gradually to 47° when the time reaches 120 s. Atomic force microscopy (AFM) results show that the root mean square (RMS) roughness was significantly higher for the He/O2 plasma treated samples than for the He plasma treated counterparts, and the surface topography of the He/O2 plasma treated PE films displays evenly distributed dome-shaped small protuberances. Chemical composition analysis reveals that the He plasma treated samples have a higher oxygen content but a clearly lower percentage of -COO than the comparable He/O2 treated samples, suggesting that differences exist in the mode of incorporating oxygen between the two gas condition plasma treatments. Electron spin resonance (ESR) results show that the free radical concentrations of the He plasma treated samples were clearly higher than those of the He/O2 plasma treated ones with other conditions unchanged. supported by the Fundamental Research Funds for the Central Universities of China (Nos. JUSRP1044 and JUSRP1045), National Natural Science Foundation of China (Nos. 51203062 and 51302110), and the Cooperative Innovation Fund, Project of Jiangsu Province, China (Nos. BY2012064, BY2013015-31 and BY2013015-32)
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Plasticized chitosan/polyolefin films produced by extrusion.
Matet, Marie; Heuzey, Marie-Claude; Ajji, Abdellah; Sarazin, Pierre
2015-03-06
Plasticized chitosan and polyethylene blends were produced through a single-pass extrusion process. Using a twin-screw extruder, chitosan plasticization was achieved in the presence of an acetic acid solution and glycerol, and directly mixed with metallocene polyethylene, mPE, to produce a masterbatch. Different dilutions of the masterbatch (2, 5 and 10 wt% of plasticized chitosan), in the presence of ethylene vinyl acetate, EVA, were subsequently achieved in single screw film extrusion. Very small plasticized chitosan domains (number average diameter <5 μm) were visible in the polymeric matrix. The resulting films presented a brown color and increasing haze with chitosan plasticized content. Mechanical properties of the mPE films were affected by the presence of plasticized chitosan, but improvement was observed as a result of some compatibility between mPE and chitosan in the presence of EVA. Finally the incorporation of plasticized chitosan affected mPE water vapor permeability while oxygen permeability remained constant. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Yang, Jun; Yang, Yu; Wu, Wei-Min; Zhao, Jiao; Jiang, Lei
2014-12-02
Polyethylene (PE) has been considered nonbiodegradable for decades. Although the biodegradation of PE by bacterial cultures has been occasionally described, valid evidence of PE biodegradation has remained limited in the literature. We found that waxworms, or Indian mealmoths (the larvae of Plodia interpunctella), were capable of chewing and eating PE films. Two bacterial strains capable of degrading PE were isolated from this worm's gut, Enterobacter asburiae YT1 and Bacillus sp. YP1. Over a 28-day incubation period of the two strains on PE films, viable biofilms formed, and the PE films' hydrophobicity decreased. Obvious damage, including pits and cavities (0.3-0.4 μm in depth), was observed on the surfaces of the PE films using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The formation of carbonyl groups was verified using X-ray photoelectron spectroscopy (XPS) and microattenuated total reflectance/Fourier transform infrared (micro-ATR/FTIR) imaging microscope. Suspension cultures of YT1 and YP1 (10(8) cells/mL) were able to degrade approximately 6.1 ± 0.3% and 10.7 ± 0.2% of the PE films (100 mg), respectively, over a 60-day incubation period. The molecular weights of the residual PE films were lower, and the release of 12 water-soluble daughter products was also detected. The results demonstrated the presence of PE-degrading bacteria in the guts of waxworms and provided promising evidence for the biodegradation of PE in the environment.
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Yong Lei; Qinglin Wu; Craig M. Clemons; Weihong Guo
2009-01-01
Blends based on recycled high density polyethylene (R-HDPE) and recycled poly(ethylene terephthalate) (R-PET) were made through reactive extrusion. The effects of maleated polyethylene (PE-g-MA), triblock copolymer of styrene and ethylene/butylene (SEBS), and 4,40-methylenedi(phenyl isocyanate) (MDI) on blend properties were studied. The 2% PE-g-MA improved the...
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Reddy, Mallampati Srinivasa; Okuda, Tetsuji; Nakai, Satoshi; Nishijima, Wataru; Okada, Mitsumasa
2011-08-01
Wet gravity separation technique has been regularly practiced to separate the polypropylene (PP) and polyethylene (PE) (light plastic films) from chlorinated plastic films (CP films) (heavy plastic films). The CP films including poly vinyl chloride (PVC) and poly vinylidene chloride (PVDC) would float in water even though its density is more than 1.0g/cm(3). This is because films are twisted in which air is sometimes entrapped inside the twisted CP films in real existing recycling plant. The present research improves the current process in separating the PP and PE from plastic packaging waste (PPW), by reducing entrapped air and by increasing the hydrophilicity of the CP films surface with ozonation. The present research also measures the hydrophilicity of the CP films. In ozonation process mixing of artificial films up to 10min reduces the contact angle from 78° to 62°, and also increases the hydrophilicity of CP films. The previous studies also performed show that the artificial PVDC films easily settle down by the same. The effect of ozonation after the wet gravity separation on light PPW films obtained from an actual PPW recycling plant was also evaluated. Although actual light PPW films contained 1.3% of CP films however in present case all the CP films were removed from the PPW films as a settled fraction in the combination process of ozonation and wet gravity separation. The combination process of ozonation and wet gravity separation is the more beneficial process in recovering of high purity PP and PE films from the PPW films. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Moudache, M; Colon, M; Nerín, C; Zaidi, F
2016-12-01
The antioxidant activity of olive leaf (OL) and cake (OC) extracts with different solvents was evaluated. 70% of aqueous ethanol extract of OL was chosen as the most antioxidant extract based on antiradical activity (DPPH) (95.4±0.3%) and oxygen radical absorbance capacity (ORAC) (0.82±0.07g equivalent Trolox per g of solution) assays. This OL extract was incorporated in two multilayer materials consisting of (i) polyethylene/polyethylene (PE/PE) film and (ii) polyethylene/paper (PE/P). These multilayers were exposed to a gas stream enriched in free radicals to evaluate the scavenging capacity of both materials. PE/PE film exhibited the highest scavenging activity of free radicals (78.8%). Migration of the phenolic compounds from olive by-products into two simulants was performed and demonstrated a non-migrating behavior. The limits of detection and quantification for oleuropein were 0.5μgkg(-1) and 1.7μgkg(-1) and for Luteolin-7-O-glucoside 1.3μgkg(-1) and 4.3μg kg(-1) respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Dolci, Paola; Tabacco, Ernesto; Cocolin, Luca; Borreani, Giorgio
2011-01-01
The aims of this study were to compare the effects of sealing forage corn with a new oxygen barrier film with those obtained by using a conventional polyethylene film. This comparison was made during both ensilage and subsequent exposure of silage to air and included chemical, microbiological, and molecular (DNA and RNA) assessments. The forage was inoculated with a mixture of Lactobacillus buchneri, Lactobacillus plantarum, and Enterococcus faecium and ensiled in polyethylene (PE) and oxygen barrier (OB) plastic bags. The oxygen permeability of the PE and OB films was 1,480 and 70 cm3 m−2 per 24 h at 23°C, respectively. The silages were sampled after 110 days of ensilage and after 2, 5, 7, 9, and 14 days of air exposure and analyzed for fermentation characteristics, conventional microbial enumeration, and bacterial and fungal community fingerprinting via PCR-denaturing gradient gel electrophoresis (DGGE) and reverse transcription (RT)-PCR-DGGE. The yeast counts in the PE and OB silages were 3.12 and 1.17 log10 CFU g−1, respectively, with corresponding aerobic stabilities of 65 and 152 h. Acetobacter pasteurianus was present at both the DNA and RNA levels in the PE silage samples after 2 days of air exposure, whereas it was found only after 7 days in the OB silages. RT-PCR-DGGE revealed the activity of Aspergillus fumigatus in the PE samples from the day 7 of air exposure, whereas it appeared only after 14 days in the OB silages. It has been shown that the use of an oxygen barrier film can ensure a longer shelf life of silage after aerobic exposure. PMID:21821764
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Fibers based on polyethylene with silicon and silicon carbide nanoparticles
NASA Astrophysics Data System (ADS)
Olkhov, A. A.; Krutikova, A. A.; Kovaleva, A. N.; Rychagov, O. V.; Ischenko, A. A.
2017-12-01
In the paper, fibrous materials based on polyethylene with nanosized silicon and silicon carbide obtained by the plasma chemical method have been obtained. The concentration of nanosilicon nanoparticles was 0.1-1.5%. Fibers absorb UV radiation in the range 200-400 nm. The size of silicon nanoparticles and dispersion in fibers are estimated by X-ray diffraction. It is shown that silicon nanoparticles exert no effect on the formation of the internal structure of the PE matrix. The degree of crystallinity, melting and crystallization temperatures remain constant. The surface properties of films are investigated by triboelectric methods and by determining the wetting angle. The surface properties of composite films do not differ from the properties of PE films with the concentration of nanoparticles from 0.1 to 1.0%. At a 1.5% content of n-SiC, the microrelief of the surface changes, and the friction coefficient of the films increases. The resulting films are recommended for application as a UV protective coating.
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-07
... Film, Sheet, and Strip From India: Preliminary Results of Countervailing Duty Administrative Review... countervailing duty (CVD) order on polyethylene terephthalate film, sheet and strip (PET film) from India for the..., the products covered are all gauges of raw, pretreated, or primed polyethylene terephthalate film...
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76 FR 8770 - Polyethylene Terephthalate (Pet) Film From Korea
Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-15
... Terephthalate (Pet) Film From Korea AGENCY: United States International Trade Commission. ACTION: Notice of... concerning the antidumping duty order on polyethylene terephthalate (PET) film from Korea. SUMMARY: The... order on PET film from Korea would be likely to lead to a continuation or recurrence of material injury...
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Ha, Jae-Won; Back, Kyeong-Hwan; Kim, Yoon-Hee; Kang, Dong-Hyun
2016-08-01
In this study, the efficacy of using UV-C light to inactivate sliced cheese inoculated with Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes and, packaged with 0.07 mm films of polyethylene terephthalate (PET), polyvinylchloride (PVC), polypropylene (PP), and polyethylene (PE) was investigated. The results show that compared with PET and PVC, PP and PE films showed significantly reduced levels of the three pathogens compared to inoculated but non-treated controls. Therefore, PP and PE films of different thicknesses (0.07 mm, 0.10 mm, and 0.13 mm) were then evaluated for pathogen reduction of inoculated sliced cheese samples. Compared with 0.10 and 0.13 mm, 0.07 mm thick PP and PE films did not show statistically significant reductions compared to non-packaged treated samples. Moreover, there were no statistically significant differences between the efficacy of PP and PE films. These results suggest that adjusted PP or PE film packaging in conjunction with UV-C radiation can be applied to control foodborne pathogens in the dairy industry. Copyright © 2016. Published by Elsevier Ltd.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-16
... Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping Duty Administrative Review... on polyethylene terephthalate film, sheet, and strip (PET film) from Brazil. This administrative... on PET film from Brazil. See Polyethylene Terephthalate Film, Sheet, and Strip From Brazil, the...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-08
... Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping Duty Administrative Review... on polyethylene terephthalate film, sheet, and strip (PET film) from Brazil. This administrative... antidumping duty order on PET film from Brazil. See Polyethylene Terephthalate Film, Sheet, and Strip From...
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Xu, Ling; Chen, Chen; Zhong, Gan-Ji; Lei, Jun; Xu, Jia-Zhuang; Hsiao, Benjamin S; Li, Zhong-Ming
2012-03-01
An easy approach was reported to achieve high mechanical properties of ultrahigh-molecular-weight polyethylene (UHMWPE)-based polyethylene (PE) blend for artificial joint application without the sacrifice of the original excellent wear and fatigue behavior of UHMWPE. The PE blend with desirable fluidity was obtained by melt mixing UHMWPE and low molecular weight polyethylene (LMWPE), and then was processed by a modified injection molding technology-oscillatory shear injection molding (OSIM). Morphological observation of the OSIM PE blend showed LMWPE contained well-defined interlocking shish-kebab self-reinforced superstructure. Addition of a small amount of long chain polyethylene (2 wt %) to LMWPE greatly induced formation of rich shish-kebabs. The ultimate tensile strength considerably increased from 27.6 MPa for conventional compression molded UHMWPE up to 78.4 MPa for OSIM PE blend along the flow direction and up to 33.5 MPa in its transverse direction. The impact strength of OSIM PE blend was increased by 46% and 7% for OSIM PE blend in the direction parallel and vertical to the shear flow, respectively. Wear and fatigue resistance were comparable to conventional compression molded UHMWPE. The superb performance of the OSIM PE blend was originated from formation of rich interlocking shish-kebab superstructure while maintaining unique properties of UHMWPE. The present results suggested the OSIM PE blend has high potential for artificial joint application. © 2012 American Chemical Society
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-27
... Film, Sheet, and Strip From India: Final Results of Countervailing Duty New Shipper Review AGENCY... shipper review of polyethylene terephthalate film, sheet and strip (PET Film) from India for SRF Limited...-1398. SUPPLEMENTARY INFORMATION: Background Since the issuance of Polyethylene Terephthalate Film...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-07
... Film, Sheet, and Strip From the United Arab Emirates; Preliminary Results of Antidumping Duty... the antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from the... covered by the order are all gauges of raw, pre- treated, or primed polyethylene terephthalate film...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-10
... Film, Sheet, and Strip from India: Final Results of Countervailing Duty Administrative Review AGENCY... of the countervailing duty order on polyethylene terephthalate film, sheet, and strip (PET film) from India for the period January 1, 2007 through December 31, 2007. See Polyethylene Terephthalate Film...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-04
... Film, Sheet, and Strip From Taiwan: Amended Final Results of Antidumping Duty Review AGENCY: Import... duty administrative review of polyethylene terephthalate film, sheet, and strip (PET Film) from Taiwan... amended (the Act). \\1\\ See Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results of...
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Kanbur, Yasin; Irimia-Vladu, Mihai; Głowacki, Eric D.; Voss, Gundula; Baumgartner, Melanie; Schwabegger, Günther; Leonat, Lucia; Ullah, Mujeeb; Sarica, Hizir; Erten-Ela, Sule; Schwödiauer, Reinhard; Sitter, Helmut; Küçükyavuz, Zuhal; Bauer, Siegfried; Sariciftci, Niyazi Serdar
2012-01-01
We report on the fabrication and performance of vacuum-processed organic field effect transistors utilizing evaporated low-density polyethylene (LD-PE) as a dielectric layer. With C60 as the organic semiconductor, we demonstrate low operating voltage transistors with field effect mobilities in excess of 4 cm2/Vs. Devices with pentacene showed a mobility of 0.16 cm2/Vs. Devices using tyrian Purple as semiconductor show low-voltage ambipolar operation with equal electron and hole mobilities of ∼0.3 cm2/Vs. These devices demonstrate low hysteresis and operational stability over at least several months. Grazing-angle infrared spectroscopy of evaporated thin films shows that the structure of the polyethylene is similar to solution-cast films. We report also on the morphological and dielectric properties of these films. Our experiments demonstrate that polyethylene is a stable dielectric supporting both hole and electron channels. PMID:23483783
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Electron emission from diamond films seeded using kitchen-wrap polyethylene
NASA Astrophysics Data System (ADS)
Varshney, D.; Makarov, V. I.; Saxena, P.; Guinel, M. J. F.; Kumar, A.; Scott, J. F.; Weiner, B. R.; Morell, G.
2011-03-01
Diamond has many potential electronic applications, but the diamond seeding methods are generally harsh on the substrates rendering them unsuitable for integration in electronics. We report a non-abrasive, scalable and economic process of diamond film seeding using kitchen-wrap polyethylene employing hot filament chemical vapour reaction of H2S/CH4/H2 gas mixtures on Cu substrates. The fabricated diamond films were characterized with scanning electron microscopy, transmission electron microscopy and Raman spectroscopy, which confirm that the deposited film consists of a microcrystalline diamond of size in the range 0.5-1.0 µm. The synthesized diamond films exhibit a turn-on field of about 8.5 V µm-1 and long-term stability. Diamond film synthesis using polyethylene will enable the integration of diamond heat sinks into high-power and high-temperature electronic devices.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-22
... Film, Sheet, and Strip From Taiwan: Final Results of Antidumping Duty Administrative Review AGENCY... review of the antidumping duty order on polyethylene terephthalate film (PET Film) from Taiwan. See Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Preliminary Results of Antidumping Duty...
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1987-03-01
contact angle with water frin the initial va: e 蕫b to the final value ’:,)3@, follows KinetiCs tnat suggest trit -no polar functional groups lisappear...PE-CO 2H in contact with liquiJs such as water and perfluorodecalin suggest that reconstruction is driven initially by ;iinimization of the...distance from the polymer- water interface can exchange ions with bulk water . Thermally reconstructed PE-CO2H is thus a new type of thin-film ion
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-09
... Film, Sheet, and Strip From India: Final Results of Antidumping Duty Administrative Review AGENCY... review of the antidumping duty order on polyethylene terephthalate film (PET Film) from India.\\1\\ This...'' section below. \\1\\ See Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-12
... Film, Sheet, and Strip From the People's Republic of China: Final Results of Antidumping Duty... polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of China (``PRC..., 2011. \\1\\ See Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-27
... Film, Sheet, and Strip From India: Final Results of Antidumping Duty New Shipper Review AGENCY: Import... polyethylene terephthalate film, sheet and strip (PET Film) from India for SRF Limited (SRF), covering the... Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of Antidumping Duty New...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-30
... Film, Sheet, and Strip From the People's Republic of China: Initiation of Antidumping Duty New Shipper... order on polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of... order on polyethylene terephthalate film, sheet, and strip from the PRC was published on November 10...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-16
... Film, Sheet, and Strip From the Republic of Korea: Revocation of Antidumping Duty Order AGENCY: Import... polyethylene terephthalate film, sheet, and strip (PET film) from the Republic of Korea. Pursuant to section...) determined that revocation of the existing antidumping duty order on polyethylene terephthalate film, sheet...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-07-15
...)] Polyethylene Terephthalate Film, Sheet, and Strip From India and Taiwan; Notice of Commission Determinations To... countervailing duty order on polyethylene terephthalate film, sheet, and strip (``PET'' film) from India and the antidumping duty orders on PET film from India and Taiwan would be likely to lead to continuation or...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-25
... Film, Sheet, and Strip From the United Arab Emirates: Final Results of Antidumping Duty Administrative... of administrative review of the antidumping duty order on polyethylene terephthalate film (PET Film... Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates: Preliminary Results of...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-11-15
... Film, Sheet, and Strip From the People's Republic of China: Extension of Time Limit for the Final... the initiation of the antidumping duty administrative review on polyethylene terephthalate film, sheet... the preliminary results of this review. See Polyethylene Terephthalate Film, Sheet, and Strip From the...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-12
... Film, Sheet and Strip From India: Extension of Time Limit for Preliminary Results of Antidumping Duty... review under the antidumping duty (AD) order on polyethylene terephthalate film, sheet and strip from... Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, In Part, of Antidumping Duty...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-04
... Film, Sheet, and Strip From the United Arab Emirates: Final Results of Antidumping Duty Administrative... administrative review of the antidumping duty order on polyethylene terephthalate film (PET Film) from the United.... \\1\\ See Polyethylene Terephthalate Film, Sheet, and Strip from the United Arab Emirates: Preliminary...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-11-19
... Film, Sheet, and Strip From the Republic of Korea: Final Results of Antidumping Duty Administrative... administrative review of the antidumping order on polyethylene terephthalate film, sheet and strip (PET film) from the Republic of Korea (Korea). See Polyethylene Terephthalate Film, Sheet, and Strip from the...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-07
... DEPARTMENT OF COMMERCE International Trade Administration [C-533-825] Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in Part, of Countervailing Duty Administrative Review... order on polyethylene terephthalate film, sheet and strip from India covering the period January 1, 2009...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-22
... Film, Sheet and Strip From India: Extension of Time Limit for Preliminary Results of Antidumping Duty... review of the antidumping duty order on polyethylene terephthalate film, sheet and strip from India for the period July 1, 2009, through December 31, 2009. See Polyethylene Terephthalate Film, Sheet and...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-25
... Film, Sheet and Strip From India: Extension of Time Limit for Preliminary Results of Antidumping Duty... polyethylene terephthalate film, sheet and strip from India for the period July 1, 2009 through December 31, 2009. See Polyethylene Terephthalate Film, Sheet and Strip from India: Initiation of Antidumping Duty...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-11-12
... Film, Sheet and Strip From India: Extension of Time Limit for Preliminary Results of Countervailing... countervailing duty order on polyethylene terephthalate film, sheet and strip from India for the period January 1, 2009, through December 31, 2009. See Polyethylene Terephthalate Film, Sheet and Strip from India...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-25
... Film, Sheet and Strip from Taiwan: Extension of Time Limit for Preliminary Results of Antidumping Duty... the antidumping duty order on polyethylene terephthalate film, sheet and strip from Taiwan for the... antidumping order on polyethylene terephthalate film, sheet and strip from Taiwan was for the period of...
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Huang, Fu-Chun; Chen, Yih-Far; Lee, Gwo-Bin
2007-04-01
This study presents a new packaging method using a polyethylene/thermoplastic elastomer (PE/TPE) film to seal an injection-molded CE chip made of either poly(methyl methacrylate) (PMMA) or polycarbonate (PC) materials. The packaging is performed at atmospheric pressure and at room temperature, which is a fast, easy, and reliable bonding method to form a sealed CE chip for chemical analysis and biomedical applications. The fabrication of PMMA and PC microfluidic channels is accomplished by using an injection-molding process, which could be mass-produced for commercial applications. In addition to microfluidic CE channels, 3-D reservoirs for storing biosamples, and CE buffers are also formed during this injection-molding process. With this approach, a commercial CE chip can be of low cost and disposable. Finally, the functionality of the mass-produced CE chip is demonstrated through its successful separation of phiX174 DNA/HaeIII markers. Experimental data show that the S/N for the CE chips using the PE/TPE film has a value of 5.34, when utilizing DNA markers with a concentration of 2 ng/microL and a CE buffer of 2% hydroxypropyl-methylcellulose (HPMC) in Tris-borate-EDTA (TBE) with 1% YO-PRO-1 fluorescent dye. Thus, the detection limit of the developed chips is improved. Lastly, the developed CE chips are used for the separation and detection of PCR products. A mixture of an amplified antibiotic gene for Streptococcus pneumoniae and phiX174 DNA/HaeIII markers was successfully separated and detected by using the proposed CE chips. Experimental data show that these DNA samples were separated within 2 min. The study proposed a promising method for the development of mass-produced CE chips.
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Methods for Assessment of Biodegradability of Plastic Films in Soil †
Yabannavar, Asha V.; Bartha, Richard
1994-01-01
Traditional and novel techniques were tested and compared for their usefulness in evaluating biodegrad-ability claims made for newly formulated “degradable” plastic film products. Photosensitized polyethylene (PE), starch-PE, extensively plasticized polyvinyl chloride (PVC), and polypropylene (PP) films were incorporated into aerobic soil. Biodegradation was measured for 3 months under generally favorable conditions. Carbon dioxide evolution, residual weight recovery, and loss of tensile strength measurements were supplemented, for some films, by gas chromatographic measurements of plasticizer loss and gel permeation chromatographic (GPC) measurement of polymer molecular size distribution. Six- and 12-week sunlight exposures of photosensitized PE films resulted in extensive photochemical damage that failed to promote subsequent mineralization in soil. An 8% starch-PE film and the plasticized PVC film evolved significant amounts of CO2 in biodegradation tests and lost residual weight and tensile strength, but GPC measurements demonstrated that all these changes were confined to the additives and the PE and PVC polymers were not degraded. Carbon dioxide evolution was found to be a useful screening tool for plastic film biodegradation, but for films with additives, polymer biodegradation needs to be confirmed by GPC. Photochemical cross-linking of polymer strands reduces solubility and may interfere with GPC measurements of polymer degradation. PMID:16349408
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POLYETHYLENE ENCAPSULATES FOR HAZARDOUS WASTE DRUMS
This capsule report summarizes studies of the use of polyethylene (P.E.) for encapsulating drums of hazardous wastes. Flat PE sheet is welded to roto moded PE containers which forms the encapsulates. Plastic pipe welding art was used, but the prototype welding apparatus required ...
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Mei, Jun; Wang, Xiuji; Xiao, Xiao; Cai, Ying; Tang, Yuhui; Chen, Pei
2017-04-01
The thermal treatment of waste electrical and electronic equipment (WEEE) is regarded as the largest potential contributor to the environmental release of polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs). Herein, the pyrolysis of decabromodiphenyl ether (deca-BDE), polyethylene (PE) and metal blends was conducted to investigate the emission characteristics of PBDD/Fs at different thermal treatment conditions. The total yield of polybrominated dibenzo-p-dioxins (PBDDs) was less than that of polybrominated dibenzofurans (PBDFs) during the pyrolysis of the PE matrix and metal blends. 2,3,7,8-TBDF and 1,2,3,7,8-PBDF were the dominant congeners emitted from the pyrolysis. Temperature, presence of oxygen and type of added metal were the critical influencing factors for the PBDD/F formation rates and speciation in the pyrolysis process. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-07
... Film, Sheet, and Strip From the Republic of Korea: Final Results of the Expedited Third Five-Year...) initiated the third sunset review of the antidumping duty order on polyethylene terephthalate film, sheet... order on polyethylene terephthalate film, sheet, and strip from the Republic of Korea, pursuant to...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-01
... DEPARTMENT OF COMMERCE International Trade Administration [C-533-825] Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for Preliminary Results of Countervailing... countervailing duty order on polyethylene terephthalate film, sheet and strip from India covering the period...
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Jia, Xiangqing; Qin, Chuan; Friedberger, Tobias; Guan, Zhibin; Huang, Zheng
2016-06-01
Polyethylene (PE) is the largest-volume synthetic polymer, and its chemical inertness makes its degradation by low-energy processes a challenging problem. We report a tandem catalytic cross alkane metathesis method for highly efficient degradation of polyethylenes under mild conditions. With the use of widely available, low-value, short alkanes (for example, petroleum ethers) as cross metathesis partners, different types of polyethylenes with various molecular weights undergo complete conversion into useful liquid fuels and waxes. This method shows excellent selectivity for linear alkane formation, and the degradation product distribution (liquid fuels versus waxes) can be controlled by the catalyst structure and reaction time. In addition, the catalysts are compatible with various polyolefin additives; therefore, common plastic wastes, such as postconsumer polyethylene bottles, bags, and films could be converted into valuable chemical feedstocks without any pretreatment.
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In-situ deposition of YBCO high-Tc superconducting thin films by MOCVD and PE-MOCVD
NASA Technical Reports Server (NTRS)
Zhao, J.; Noh, D. W.; Chern, C.; Li, Y. Q.; Norris, P. E.; Kear, B.; Gallois, B.
1991-01-01
Metal-Organic Chemical Vapor Deposition (MOCVD) offers the advantages of a high degree of compositional control, adaptability for large scale production, and the potential for low temperature fabrication. The capability of operating at high oxygen partial pressure is particularly suitable for in situ formation of high temperature superconducting (HTSC) films. Yttrium barium copper oxide (YBCO) thin films having a sharp zero-resistance transition with T(sub c) greater than 90 K and J(sub c) of approximately 10(exp 4) A on YSZ have been prepared, in situ, at a substrate temperature of about 800 C. Moreover, the ability to form oxide films at low temperature is very desirable for device applications of HTSC materials. Such a process would permit the deposition of high quality HTSC films with a smooth surface on a variety of substrates. Highly c-axis oriented, dense, scratch resistant, superconducting YBCO thin films with mirror-like surfaces have been prepared, in situ, at a reduced substrate temperature as low as 570 C by a remote microwave-plasma enhanced metal-organic chemical vapor deposition (PE-MOCVD) process. Nitrous oxide was used as a reactant gas to generate active oxidizing species. This process, for the first time, allows the formation of YBCO thin films with the orthorhombic superconducting phase in the as-deposited state. The as-deposited films grown by PE-MOCVD show attainment of zero resistance at 72 K with a transition width of about 5 K. MOCVD was carried out in a commercial production scale reactor with the capability of uniform deposition over 100 sq cm per growth run. Preliminary results indicate that PE-MOCVD is a very attractive thin film deposition process for superconducting device technology.
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AuNP-PE interface/phase and its effects on the tensile behaviour of AuNP-PE composites
NASA Astrophysics Data System (ADS)
Wang, Yue; Wang, Ruijie; Wang, Chengyuan; Yu, Xiaozhu
2018-06-01
A comprehensive study was conducted for a gold nanoparticle (AuNP)-polyethylene (PE) composite. Molecular dynamic (MD) simulations were employed to construct the AuNP-PE systems, achieve their constitutive relations, and measure their tensile properties. Specifically, the AuNP-PE interface/phase was studied via the mass density profile, and its effect was evaluated by comparing the composite with a pure PE matrix. These research studies were followed by the study of the fracture mechanisms and the size and volume fraction effects of AuNPs. Efforts were also made to reveal the underlying physics of the MD simulations. In the present work, an AuNP-PE interface and a densified PE interphase were achieved due to the AuNP-PE van der Waals interaction. Such an interface/phase is found to enhance the Young's modulus and yield stress but decrease the fracture strength and strain.
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Improvement of barrier properties of rotomolded PE containers with nanoclay
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jamshidi, Shadi; Sundararaj, Uttandaraman, E-mail: u.sundararaj@ucalgary.ca
Polyethylene (PE) is widely used to make bulk containers in rotational molding process. The challenge in this study is to improve permeation resistance of PE to hydrocarbon solvents and gases. Adding organomodified clay improves the thermal, barrier and mechanical properties of PE. In fact, clay layers create a tortuous path against the permeant, yielding better barrier properties. Due to the non-polar hydrophobic nature of PE and polar hydrophilic structure of clay minerals, the compatibilizer plays a crucial role to enhance the dispersion level of clay in the matrix. In this study High Density Polyethylene (HDPE) and Linear Low Density Polyethylenemore » (LLDPE) layered silicate nanocomposite were melt-compounded with two concentrations of organomodified clay (2 and 4 wt. %). The interaction between nanoclay, compatibilizer and rotomolding grade of PE were examined by using X-ray diffraction, transmission electron microscopy (TEM) and rheology test. Rheology was used to determine the performance of our material at low shear processing condition.« less
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-01
... DEPARTMENT OF COMMERCE International Trade Administration [A-533-824] Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for Preliminary Results of Antidumping Duty... polyethylene terephthalate film, sheet and strip from India covering the period July 1, 2009, through June 30...
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Effective Identification on Adulteration of Polyethylene With Post-consumer Ones
NASA Astrophysics Data System (ADS)
Zhao, S.; Qin, W. B.; Guo, J. F.; Liu, J.; Wang, Y. L.; Zhang, W.; Zhao, X. Y.; Wang, L.
2018-05-01
This paper mainly describes the effective identification of the adulteration of polyethylene with post-consumer ones. Degradation would be happened when multiple processings occurred. The melt flow index (MFI) analysis, thermal gravimetric analysis (TGA), differential scanning calorimeter (DSC) were used to characterize the processability and thermal stabilities of virgin polyethylene and recycled polyethylene which adulterated post-consumer PE. The results indicated that MFI of PE increased with the increasing doping content. Adulterating reclaimed PE had effects on the thermal stability of PE, which led to lower thermal decomposition temperature. Melting peak of recycled LLDPE varied from merely single to double, which differently compared differently with virgin LLDPE. Besides, with the doping content of post-consumer LDPE, the melting temperature had a decreasing tendency.
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Quiroz-Castillo, Jesús Manuel; Rodríguez-Félix, Dora Evelia; Grijalva-Monteverde, Heriberto; Lizárraga-Laborín, Lauren Lucero; Castillo-Ortega, María Mónica; del Castillo-Castro, Teresa; Rodríguez-Félix, Francisco; Herrera-Franco, Pedro Jesús
2014-01-01
The use of mixtures of synthetic and natural polymers is a potential option to reduce the pollution by plastic waste. In this work, the method for the chemical modification of chitosan with poly(lactic acid) was developed; then, the preparation of films of blends of polyethylene and chitosan-poly(lactic acid) produced by an extrusion method using polyethylene-graft maleic anhydride as a compatibilizer. It was possible to obtain films with a maximum content of 20 wt% and 30 wt%, chitosan, with and without compatibilizer, respectively. Scanning electron microscope (SEM) analysis showed a homogeneous surface on all films. The addition of the compatibilizer had a significant effect on the mechanical properties of the films, such as an increase in Young’s modulus and a decrease in the elongation at break; additionally, the compatibilizer promotes thermal degradation in a single step and gives the film a slight increase in thermal resistance. These results are attributed to an improved interaction in the interface of polyethylene and chitosan-poly(lactic acid), promoted by the compatibilizer. PMID:28787928
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Jia, Xiangqing; Qin, Chuan; Friedberger, Tobias; Guan, Zhibin; Huang, Zheng
2016-01-01
Polyethylene (PE) is the largest-volume synthetic polymer, and its chemical inertness makes its degradation by low-energy processes a challenging problem. We report a tandem catalytic cross alkane metathesis method for highly efficient degradation of polyethylenes under mild conditions. With the use of widely available, low-value, short alkanes (for example, petroleum ethers) as cross metathesis partners, different types of polyethylenes with various molecular weights undergo complete conversion into useful liquid fuels and waxes. This method shows excellent selectivity for linear alkane formation, and the degradation product distribution (liquid fuels versus waxes) can be controlled by the catalyst structure and reaction time. In addition, the catalysts are compatible with various polyolefin additives; therefore, common plastic wastes, such as postconsumer polyethylene bottles, bags, and films could be converted into valuable chemical feedstocks without any pretreatment. PMID:27386559
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-29
... DEPARTMENT OF COMMERCE International Trade Administration [A-520-803] Polyethylene Terephthalate Film, Sheet and Strip From the United Arab Emirates: Extension of Time Limit for Preliminary Results of... polyethylene terephthalate film, sheet and strip from the United Arab Emirates (UAE) for the period November 01...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-16
... Film, Sheet and Strip From Brazil: Preliminary Results of Antidumping Duty Administrative Review; 2011...Pont Teijin Films, Mitsubishi Polyester Film, Inc., SKC, Inc., and Toray Plastics (America), Inc... the antidumping duty order on polyethylene terephthalate film, sheet and strip (PET film) from Brazil...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-16
... Film, Sheet, and Strip From the People's Republic of China: Preliminary Results and Preliminary... antidumping duty order on polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's... Teijin Films, Mitsubishi Polyester Film, Inc., SKC, Inc., and Toray Plastics (America), Inc...
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In Situ deposition of YBCO high-T(sub c) superconducting thin films by MOCVD and PE-MOCVD
NASA Technical Reports Server (NTRS)
Zhao, J.; Noh, D. W.; Chern, C.; Li, Y. Q.; Norris, P.; Gallois, B.; Kear, B.
1990-01-01
Metalorganic Chemical Vapor Deposition (MOCVD) offers the advantages of a high degree of compositional control, adaptability for large scale production, and the potential for low temperature fabrication. The capability of operating at high oxygen partial pressure is particularly suitable for in situ formation of high temperature superconducting (HTSC) films. Yttrium barium copper oxide (YBCO) thin films having a sharp zero-resistance transition with T( sub c) greater than 90 K and Jc approx. 10 to the 4th power A on YSZ have been prepared, in situ, at a substrate temperature of about 800 C. Moreover, the ability to form oxide films at low temperature is very desirable for device applications of HTSC materials. Such a process would permit the deposition of high quality HTSC films with a smooth surface on a variety of substrates. Highly c-axis oriented, dense, scratch resistant, superconducting YBCO thin films with mirror-like surfaces have been prepared, in situ, at a reduced substrate temperature as low as 570 C by a remote microwave-plasma enhanced metalorganic chemical vapor deposition (PE-MOCVD) process. Nitrous oxide was used as a reactant gas to generate active oxidizing species. This process, for the first time, allows the formation of YBCO thin films with the orthorhombic superconducting phase in the as-deposited state. The as-deposited films grown by PE-MOCVD show attainment of zero resistance at 72 K with a transition width of about 5 K. MOCVD was carried out in a commercial production scale reactor with the capability of uniform deposition over 100 sq cm per growth run. Preliminary results indicate that PE-MOCVD is a very attractive thin film deposition process for superconducting device technology.
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Borrelli, Raffaella; Tcaciuc, A Patricia; Verginelli, Iason; Baciocchi, Renato; Guzzella, Licia; Cesti, Pietro; Zaninetta, Luciano; Gschwend, Philip M
2018-06-01
Laboratory and field studies were used to evaluate the performance of low-density polyethylene (PE) passive samplers for assessing the freely dissolved concentrations of DDT and its degradates (DDD and DDE, together referred to as DDx) in an Italian lake environment. We tested commercially available 25 μm thick PE sheets as well as specially synthesized, 10 μm thick PE films which equilibrated with their surroundings more quickly. We measured PE-water partitioning coefficients (K pew ) of the 10 μm thick PE films, finding good correspondence with previously reported values for thicker PE. Use of the 10 μm PE for ex situ sampling of a lake sediment containing DDx in laboratory tumbling experiments showed repeatability of ±15% (= standard deviation/mean). Next, we deployed replicate 10 μm and 25 μm PE samplers (N = 4 for 10 d and for 30 d) in the water and sediment of a lake located in northern Italy; the results showed dissolved DDx concentrations in the picogram/L range in porewater and the bottom water. Values deduced from 10 μm thick PE films compared well (95% of all comparison pairs matched within a factor of 5) with those obtained using PE films of 25 μm thickness when dissolved DDx concentrations were estimated using performance reference compound (PRC) corrections, whether left at the bed-water interface for 10 or 30 days. These results demonstrated the potential of this sampling method to provide estimation of the truly dissolved DDx concentrations, and thereby the mobile and bio-available fractions in both surface waters and sediment beds. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-28
... Film, Sheet, and Strip From India: Preliminary Results of Antidumping Duty New Shipper Review AGENCY... antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET film) from India in response... Teijin Films, Mitsubishi Polyester Film, Inc., SKC, Inc. and Toray Plastics (America), Inc. (petitioners...
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Biocompatibility of modified ultra-high-molecular-weight polyethylene
NASA Astrophysics Data System (ADS)
Novotná, Z.; Lacmanová, V.; Rimpelová, S.; Juřik, P.; Polívková, M.; Å vorčik, V.
2016-09-01
Ultra-high-molecular-weight polyethylene (UHMWPE, PE) is a synthetic polymer used for biomedical applications because of its high impact resistance, ductility and stability in contact with physiological fluids. Therefore this material is being used in human orthopedic implants such as total joint replacements. Surface modification of this material relates to changes of its surface hydrophilicity, energy, microstructure, roughness, and morphology, all influencing its biological response. In our recent work, PE was treated by an Ar+ plasma discharge and then grafted with biologically active polyethylene glycol in order to enhance adhesion and proliferation of mouse fibroblast (L929). The surface properties of pristine PE and its grafted counterparts were studied by goniometry (surface wettability). Furthermore, Atomic Force Microscopy was used to determine the surface morphology and roughness. The biological response of the L929 cell lines seeded on untreated and plasma treated PE matrices was quantified in terms of the cell adhesion, density, and metabolic activity. Plasma treatment leads to the ablation of the polymer surface layers. Plasma treatment and subsequent poly(ethylene glycol) grafting lead to dramatic changes in the polymer surface morphology and roughness. Biological tests, performed in vitro, show increased adhesion and proliferation of cells on modified polymers. Grafting with poly(ethylene glycol) increases cell proliferation compared to plasma treatment.
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Pomerantsev, Alexey L; Rodionova, Oxana Ye; Skvortsov, Alexej N
2017-08-01
Investigation of a sample covered by an interfering layer is required in many fields, e.g., for process control, biochemical analysis, and many other applications. This study is based on the analysis of spectra collected by near-infrared (NIR) diffuse reflectance spectroscopy. Each spectrum is a composition of a useful, target spectrum and a spectrum of an interfering layer. To recover the target spectrum, we suggest using a new phenomenological approach, which employs the multivariate curve resolution (MCR) method. In general terms, the problem is very complex. We start with a specific problem of analyzing a system, which consists of several layers of polyethylene (PE) film and underlayer samples with known spectral properties. To separate information originating from PE layers and the target, we modify the system versus both the number of the PE layers as well as the reflectance properties of the target sample. We consider that the interfering spectrum of the layer can be modeled using three components, which can be tentatively called transmission, absorption, and scattering contributions. The novelty of our approach is that we do not remove the reflectance and scattering effects from the spectra, but study them in detail aiming to use this information to recover the target spectrum.
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-09
... Film, Sheet, and Strip From Taiwan; Preliminary Results of Antidumping Duty Administrative Review; 2011... duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from Taiwan. The period of.... (SMTC) (collectively, Shinkong), producer and exporter of PET Film from Taiwan. The Department...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-05
... Film, Sheet, and Strip From Taiwan: Preliminary Results of Antidumping Duty Administrative Review... on polyethylene terephthalate film, sheet, and strip (PET Film) from Taiwan. The [[Page 47541..., Shinkong), and Nan Ya Plastics Corporation, Ltd. (Nan Ya), producers and exporters of PET Film from Taiwan...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-16
... Film, Sheet, and Strip From Taiwan: Preliminary Results of Antidumping Duty Administrative Review... antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from Taiwan. This...), producers and exporters of PET Film from Taiwan. The Department preliminarily determines that sales of PET...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-05
... Film, Sheet, and Strip From India: Preliminary Results of Antidumping Duty Administrative Review AGENCY... on polyethylene terephthalate film, sheet, and strip (PET Film) from India. This review covers one respondent, Ester Industries Ltd. (Ester), a producer and exporter of PET Film from India. The Department...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-30
... Film, Sheet, and Strip From Brazil: Notice of Rescission of Antidumping Duty Administrative Review... response to a request from DuPont Teijin Films, Mitsubishi Polyester Film, Inc., SKC, Inc., and Toray... an administrative review of the antidumping duty order on polyethylene terephthalate film, sheet, and...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-11
... Film, Sheet, and Strip From India: Final Results of Administrative Review of the Antidumping Duty Order... administrative review of the antidumping duty order on polyethylene terephthalate film (PET Film) from India.\\1\\ This review covers three respondents, Jindal Poly Films Ltd (Jindal), Polyplex Corporation Ltd...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-07
... Film, Sheet, and Strip From India: Preliminary Results of Antidumping Duty Administrative Review; 2011... duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from India. The period of... Films Limited (Jindal), SRF Limited (SRF), and Polyplex Corporation Ltd. (Polyplex). Jindal and SRF were...
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Facile Fabrication of a Polyethylene Mesh for Oil/Water Separation in a Complex Environment.
Zhao, Tianyi; Zhang, Dongmei; Yu, Cunming; Jiang, Lei
2016-09-14
Low cost, eco-friendly, and easily scaled-up processes are needed to fabricate efficient oil/water separation materials, especially those useful in harsh environments such as highly acidic, alkaline, and salty environments, to deal with serious oil spills and industrial organic pollutants. Herein, a highly efficient oil/water separation mesh with durable chemical stability was fabricated by simply scratching and pricking a conventional polyethylene (PE) film. Multiscaled morphologies were obtained by this scratching and pricking process and provided the mesh with a special wettability performance termed superhydrophobicity, superoleophilicity, and low water adhesion, while the inert chemical properties of PE delivered chemical etching resistance to the fabricated mesh. In addition to a highly efficient oil/corrosive liquid separation, the fabricated PE mesh was also reusable and exhibited ultrafast oil/water separation solely by gravity. The easy operation, chemical durability, reusability, and efficiency of the novel PE mesh give it high potential for use in industrial and consumer applications.
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NASA Astrophysics Data System (ADS)
Podzorova, M. V.; Tertyshnaya, Yu. V.; Pantyukhov, P. V.; Shibryaeva, L. S.; Popov, A. A.; Nikolaeva, S.
2016-11-01
Influence of different environmental factors on the degradation of film samples based on polylactic acid and low density polyethylene with the addition of oxidized polyethylene was studied in this work. Different methods were used to find the relationship between degradation and ultraviolet, moisture, oxygen. It was found that the addition of oxidized polyethylene, used as a model of recycled polyethylene, promotes the degradation of blends.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-17
... Film, Sheet, and Strip From the United Arab Emirates: Preliminary Results of Antidumping Duty... antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from the United Arab...), producers and exporters of PET Film from the UAE. The Department preliminarily determines that sales of PET...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-24
... Film, Sheet, and Strip From the United Arab Emirates; Preliminary Results of Antidumping Duty... film, sheet, and strip (PET Film) from the United Arab Emirates (UAE). The period of review (POR) is... covered by the order are all gauges of raw, pre- treated, or primed polyethylene terephthalate film...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-07
... Film, Sheet, and Strip From the United Arab Emirates: Preliminary Results of Antidumping Duty... antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from the United Arab Emirates (UAE). This review covers the respondent, JBF RAK LLC (JBF), a producer and exporter of PET Film...
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Iqbal, Muhammad Z.; Abdala, Ahmed A.; Mittal, Vikas
Poor dispersion of graphene in non-polar polymer matrices creates composites with limited applications. A method to improve the dispersion of graphene in polyethylene (PE) via blending PE with oxidized PE (OPE) is examined. Graphene was produced by simultaneous thermal exfoliation and reduction of graphite oxide. Nanocomposites of graphene with PE as well as graphene with PE/OPE-blends were prepared by solvent blending. Improved dispersion of graphene in PE/OPE blends substantially decreases percolation from both rheological (0.3 vol%) and electrical (0.13 vol%) measurements compared to neat PE nanocomposites (1 and 0.29 vol%), respectively. A universal Brownian dispersion of graphene in polymers wasmore » concluded similar to that of nanotubes, following the Doi-Edwards theory. Micromechanical models, such as Mori-Tanaka and Halpin-Tsai models, modeled the mechanical properties of the nanocomposites. The nanocomposites microstructure, studied by small angle x-ray scattering, confirmed better dispersion of graphene at lower loadings and the formation of surface fractals in the blend/graphene nanocomposites; whereas only mass fractals were observed in neat PE/graphene nanocomposites.« less
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-11
... Film, Sheet and Strip From India: Partial Rescission of Countervailing Duty Administrative Review; 2011... an administrative review of the countervailing duty (CVD) order on polyethylene terephthalate film...), SRF Limited (SRF), and Jindal Poly Films Limited of India (Jindal). The Department also received...
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77 FR 1668 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in Part, of...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-11
... Film, Sheet and Strip From India: Rescission, in Part, of Countervailing Duty Administrative Review... (CVD) order on polyethylene terephthalate film, sheet and strip from India covering the period January... companies: Ester Industries Limited (Ester), Garware Polyester Ltd. (Garware), Jindal Poly Films Limited of...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-21
... Film, Sheet and Strip from India: Preliminary Intent to Rescind Countervailing Duty Administrative... the countervailing duty (CVD) order on polyethylene terephthalate film, sheet and strip from India...), Jindal Poly Films Limited of India (Jindal), Polyplex Corporation Ltd. (Polyplex), and SRF Limited (SRF...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-20
... Film, Sheet and Strip From India: Rescission, In Part, of Countervailing Duty Administrative Review... an administrative review of the countervailing duty (CVD) order on polyethylene terephthalate film...., Jindal Poly Films Limited of India, Polyplex Corporation Ltd., and SRF Limited. The Department also...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-02
... Film, Sheet and Strip From India: Rescission of Countervailing Duty Administrative Review AGENCY... (CVD) order on polyethylene terephthalate film, sheet and strip from India covering the period January... companies: Ester Industries Limited (Ester), Garware Polyester Ltd. (Garware), Jindal Poly Films Limited of...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-14
... Film, Sheet, and Strip from the Republic of Korea: Preliminary Results of Antidumping Duty... on polyethylene terephthalate film, sheet and strip (PET film) from the Republic of Korea (Korea... of ``Opportunity to Request Administrative Review'' of the antidumping duty order on PET film from...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-11-08
... Terephthalate Film, Sheet and Strip From India and Taiwan: Preliminary Results of the Second Sunset Review of... antidumping duty orders on Polyethylene Terephthalate Film, Sheet and Strip (``PET Film'') from India and...) 482-2371, respectively. SUPPLEMENTARY INFORMATION: Background The antidumping duty orders on PET Film...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-28
... Film, Sheet and Strip from Taiwan: Partial Rescission of the Antidumping Duty Administrative Review... an administrative review of the antidumping duty (AD) order on polyethylene terephthalate film, sheet... Shinkong.\\3\\ On September 26, 2012, DuPont Teijin Films, one of the petitioners who requested the review...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-11
... Film, Sheet and Strip From India: Partial Rescission of Antidumping Duty Administrative Review; 2011...) order on polyethylene terephthalate film, sheet and strip from India covering the period July 1, 2011...), Polyplex Corporation Ltd. (Polyplex), SRF Limited (SRF), and Jindal Poly Films Limited of India (Jindal).\\3...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-08
... Film, Sheet, and Strip From the Republic of Korea: Preliminary Results of Antidumping Duty... antidumping duty order on polyethylene terephthalate film, sheet and strip (PET film) from the Republic of... antidumping duty order on PET film from Korea. See Antidumping or Countervailing Duty Order, Finding, or...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-05
... Film, Sheet, and Strip From Korea: Notice of Rescission of Antidumping Duty Administrative Review... administrative review of the antidumping duty order on polyethylene terephthalate film, sheet, [[Page 75871
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Park, Jong-Seok; Lim, Youn-Mook; Nho, Young-Chang
2015-01-01
Polyurethane (PU) is a very popular polymer that is used in a variety of applications due to its good mechanical, thermal, and chemical properties. However, PU recycling has received significant attention due to environmental issues. In this study, we developed a recycling method for waste PU that utilizes the radiation grafting technique. Grafting of waste PU was carried out using a radiation technique with polyethylene-graft-maleic anhydride (PE-g-MA). The PE-g-MA-grafted PU/high density polyethylene (HDPE) composite was prepared by melt-blending at various concentrations (0–10 phr) of PE-g-MA-grafted PU. The composites were characterized using fourier transform infrared spectroscopy (FT-IR), and their surface morphology and thermal/mechanical properties are reported. For 1 phr PU, the PU could be easily introduced to the HDPE during the melt processing in the blender after the radiation-induced grafting of PU with PE-g-MA. PE-g-MA was easily reacted with PU according to the increasing radiation dose and was located at the interface between the PU and the HDPE during the melt processing in the blender, which improved the interfacial interactions and the mechanical properties of the resultant composites. However, the elongation at break for a PU content >2 phr was drastically decreased. PMID:28788022
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-11-18
... Film, Sheet, and Strip From Korea: Final Results of Antidumping Duty Administrative Review and... terephthalate film, sheet, and strip (PET film) from Korea, covering the June 1, 2009, to May 31, 2010, period of review (POR).\\1\\ \\1\\ See Polyethylene Terephthalate Film, Sheet, and Strip from the Republic of...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-11
... Film, Sheet, and Strip From Taiwan: Final Results of Antidumping Duty Administrative Review; 2010-2011... administrative review of the antidumping duty order on polyethylene terephthalate film (PET Film) from Taiwan.\\1...), producers and exporters of PET Film from Taiwan. Based on the results of our analysis of the comments...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-20
... Film, Sheet and Strip From India: Rescission, in Part, of Antidumping Duty Administrative Review AGENCY... review of the antidumping duty (AD) order on polyethylene terephthalate film, sheet and strip from India... Petitioners \\1\\ for five companies: Ester Industries Limited, Garware Polyester Ltd., Jindal Poly Films...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-03
... Film, Sheet, and Strip From the People's Republic of China: Extension of Preliminary Results of... for the preliminary results of the administrative review of polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of China (``PRC''). This review covers the period...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-09
... Terephthalate Film, Sheet and Strip from India: Initiation of Antidumping Duty and Countervailing Duty New... of the antidumping (AD) and countervailing duty (CVD) orders on Polyethylene Terephthalate Film, Sheet and Strip (PET Film) from India. The Department determines that these requests are sufficient to...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-18
... Film, Sheet, and Strip From the People's Republic of China: Extension of Preliminary Results of... for the preliminary results of the administrative review of polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of China (``PRC''). This review covers the period...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-22
... Film, Sheet, and Strip From the People's Republic of China: Final Results of the First Antidumping Duty... of the first administrative review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of China (``PRC'').\\1\\ We gave interested...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-11-25
... Film, Sheet, and Strip From Brazil: Final Results of Antidumping Duty Administrative Review AGENCY... administrative review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET film) from Brazil for the period November 1, 2009 through October 31, 2010. We gave interested parties...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-25
... Film, Sheet and Strip From India: Rescission, in Part, of Antidumping Duty Administrative Review AGENCY... polyethylene terephthalate film, sheet and strip from India covering the period July 1, 2010, through June 30...), Garware Polyester Ltd. (Garware), Jindal Poly Films Limited of India (Jindal), Polyplex [[Page 3731...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-02
... Film, Sheet, and Strip From Brazil: Final Results of Antidumping Duty Administrative Review AGENCY... administrative review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET film) from Brazil for the period November 6, 2008, through October 31, 2009. We gave interested parties...
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Frick, Chris; Dietz, Andrew C; Merritt, Katharine; Umbreit, Thomas H; Tomazic-Jezic, Vesna J
2006-01-01
The main causes for the long-term prosthetic implants' failure are the body's reaction to the implanted material or mechanical stress on the device resulting in the formation of wear particles. Particulate wear debris attracts macrophages, and depending on the chemical composition of the material and particle size, various levels of inflammatory response may occur. While transient inflammation is common, development of chronic inflammation may have serious consequences, leading to implant failure. Such a process may also cause systemic changes to immune functions and long-term effects on the host immune responses. In this study, we evaluated the effects of polystyrene (PS), polyethylene (PE), and polymethylmethacrylate (PMMA) particles on macrophage function and the generation of T-cell responses. Particles of various diameters were injected intraperitoneally into Balb/c mice, and immune functions were examined at 3, 10, and 21 days after the injection. The intensity of phagocytosis by peritoneal exudate cells (PECs) and the proliferative response of spleen cells from treated mice were evaluated. Enumeration of PECs revealed an increase in the total number of cells. Mice injected with PS or PE particles had a higher percentage of cells containing particles than PMMA-injected mice. Macrophages with PS or PE particles tended to adhere to and/or infiltrate peritoneal fibro-fatty tissues surrounding the spleen and pancreas, while the PMMA-carrying macrophages infiltrated the spleen, resulting in an increase of spleen size and "weight. The spleen cell proliferation assay revealed only mild and transient effects on the mitogen response in both PE and PS particle-injected mice. However, in the PMMA-injected mice we observed a lasting increase of the Con A response and a decrease of the LPS response. In vitro exposure of PECs from untreated mice showed a dose-response pattern in nitric oxide (NO) and TNFalpha production. While exposure to either PMMA or PE induced
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Dye injection for predicting pesticide movement in micro-irrigated polyethylene film mulch beds.
Csinos, Alex S; Laska, James E; Childers, Stan
2002-04-01
A new method is described for tracing water movement in polyethylene film covered soil beds. Dye was delivered via a drip tape micro-irrigation system which was placed in the bed as the soil beds were shaped and covered with polyethylene film. The dye was injected into the system and irrigated with water for 4-24 h at 0.41-1.38 bar (41-138 kPa) pressure depending on the experiment. The dye appeared as blue circles on the soil surface within 20 min of injection and produced a three-dimensional pattern in the soil profile. Injection-irrigation-pressure scenarios were evaluated by measuring dye movement directly below and between emitters by sliding fabricated blades vertically into the bed at the desired examination point and excavating the soil away from the blade. The dye typically produced a U shape on the face of the bed and the area was calculated for each of these exposed faces. The area increased as the length of irrigation and water pressure increased. Interrupted irrigation (pulsing) scenarios did not alter the calculated areas encompassed by the dye compared to uninterrupted irrigation scenarios. The blue dye provided a direct, inexpensive and easy method of visualizing water movement in soil beds. This information will be used to optimize application of emulsifiable plant-care products in polyethylene film mulch beds.
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-12
... Film, Sheet, and Strip From the People's Republic of China: Final Results of the 2009-2010 Antidumping... review of polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of... this review. We invited interested parties to comment on our Preliminary Results. Based on our analysis...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-10
... Film, Sheet, and Strip From the Republic of Korea: Initiation and Preliminary Results of Antidumping... changed circumstances review of the antidumping duty order on polyethylene terephthalate film, sheet and strip (PET film) from the Republic of Korea (Korea) pursuant to section 751(b) of the Tariff Act of 1930...
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USDA-ARS?s Scientific Manuscript database
Southern California strawberries are planted in raised-beds covered by polyethylene (PE) film and typically are irrigated with two drip lines placed near the bed surface. To control soil-borne pests, fumigants are commonly applied through the drip lines prior to transplanting strawberries, but effic...
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USDA-ARS?s Scientific Manuscript database
Drip fumigation is commonly used for controlling soilborne pests in raised-bed strawberry production systems in California. However, the high emission loss and poor pest control indicate that the current fumigation practice with two drip tapes and polyethylene film (PE) covering need to be improved....
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Sato, Harumi; Higashi, Noboru; Ikehata, Akifumi; Koide, Noriko; Ozaki, Yukihiro
2007-07-01
The aim of the present study is to propose a totally new technique for the utilization of far-ultraviolet (UV) spectroscopy in polymer thin film analysis. Far-UV spectra in the 120-300 nm region have been measured in situ for six kinds of commercial polymer wrap films by use of a novel type of far-UV spectrometer that does not need vacuum evaporation. These films can be straightforwardly classified into three groups, polyethylene (PE) films, polyvinyl chloride (PVC) films, and polyvinylidene chloride (PVDC) films, by using the raw spectra. The differences in the wavelength of the absorption band due to the sigma-sigma* transition of the C-C bond have been used for the classification of the six kinds of films. Using this method, it was easy to distinguish the three kinds of PE films and to separate the two kinds of PVDC films. Compared with other spectroscopic methods, the advantages of this technique include nondestructive analysis, easy spectral measurement, high sensitivity, and simple spectral analysis. The present study has demonstrated that far-UV spectroscopy is a very promising technique for polymer film analysis.
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Kinetics and microscopic processes of long term fracture in polyethylene piping materials
NASA Astrophysics Data System (ADS)
Brown, N.; Lu, X.
1992-07-01
The report contains 9 completed works as follows: The Dependence of Slow Crack Growth in a Polyethylene Copolymer on Testing Temperature and Morphology; A Test of Slow Crack Growth Failure of PE Under Constant Load; Effect of Annealing on Slow Crack Growth in an Ethylene-Hexene Copolymer; The Fundamental Material Parameters that Govern Slow Crack Growth in Linear Polyethylene; Slow Crack Growth in Blends of HDPE and UHMWPE; The Mechanism of Fatigue Failure in a Polyethylene Copolymer; PENT Quality Control Test for PE Gas Pipes and Resins; International Round Robin Study of a Fatigue Test Approach to the Ranking of Polyethylene Pipe Material; and Proposed ASTM Specification for ASTM F17.40 Test Methods Committee.
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An assessment of athrombogenic properties of electret polyethylene film.
Lowkis, B; Szymonowicz, M
1998-01-01
This paper shows the results of an investigation into the effect of an electric charge on blood platelet adhesion. All of the experiments were made on a polyethylene film. The electrets were formed using the electron beam method. The assessment of the electret effect on blood platelet adhesion was performed microscopically. It was found out that an electric charge plays a major role in the process of adhesion of blood morphological elements.
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Effects of polyethylene film wrap on cooler shrink and the microbial status of beef carcasses.
Sampaio, Guilherme S L; Pflanzer-Júnior, Sérgio B; Roça, Roberto de O; Casagrande, Leandro; Bedeschi, Elaine A; Padovani, Carlos R; Miguel, Giulianna Z; Santos, Carolina T; Girão, Lucio V C; Miranda, Zander B; Franco, Robson M
2015-02-01
The present study evaluated the use of polyethylene film wrapping of beef half carcasses and its effects on cooler shrink, cooling characteristics and microbial status of the half carcasses. Film wrapping reduced cooler shrink by 55.2%, 43.1%, 36.0% and 30% after 24, 48, 72 and 96 h of cooling, respectively, compared to the unwrapped half carcasses, whereas the surface water activity showed no significant differences among the time periods. The wrapped half carcasses had a lower cooling rate and higher surface and internal temperatures. The highest values of the aerobic mesophiles, Staphylococcus aureus and Enterobacteriaceae were found in the half carcasses wrapped in film. No significant differences were found in the values of Escherichia coli. The polyethylene film was effective in reducing cooler shrink; however, it caused a delay in cooling, thereby enabling greater microbial occurrences and counts and impairing the hygienic and sanitary conditions of the carcasses, which may be an impediment to the practical application of this technology.
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-21
... Film, Sheet, and Strip From the United Arab Emirates: Final Results of Antidumping Duty Administrative... preliminary results of administrative review of the antidumping duty order on polyethylene terephthalate film (PET Film) from the United Arab Emirates.\\1\\ This review covers two producers/exporters of subject...
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Marchetti, Fabio; Palmucci, Jessica; Pettinari, Claudio; Pettinari, Riccardo; Marangoni, Mirko; Ferraro, Stefano; Giovannetti, Rita; Scuri, Stefania; Grappasonni, Iolanda; Cocchioni, Mario; Maldonado Hodar, Francisco José; Gunnella, Roberto
2016-11-02
Novel composite materials PEn (n = 1-9) have been prepared by an easily up-scalable embedding procedure of three different families of Ag(I) acylpyrazolonato complexes in polyethylene (PE) matrix. In details, PE1-PE3 composites contain polynuclear [Ag(Q R )] n complexes, PE4-PE6 contain mononuclear [Ag(Q R )(L) m ] complexes and PE7-PE9 are loaded with mononuclear [Ag(Q R ) (PPh 3 ) 2 ] complexes, respectively (where L = 1-methylimidazole or 2-ethylimidazole, m = 1 or 2, and HQ R = 1-phenyl-3-methyl-4-RC(═O)-5-pyrazolone, where in detail HQ fb , R = -CF 2 CF 2 CF 3 ; HQ cy , R = -cyclo-C 6 H 11 ; HQ be , R = -C(H)═C(CH 3 ) 2 ). The PEn composites, prepared by using a 1:1000 w/w silver additive/polyethylene ratio, have been characterized in bulk by IR spectroscopy and TGA analyses, which confirmed that the properties of polyethylene matrix are essentially unchanged. AFM, SEM, and EDX surface techniques show that silver additives form agglomerates with dimensions 10-100 μm on the polyethylene surface, with a slight increment of surface roughness of pristine plastic within 50 nm. However, the elastic properties of the composites are essentially the same of PE. The antibacterial activity of all composites has been tested against three bacterial strains (E. coli, P. aeruginosa and S. aureus) and results show that two classes of composites, PE1-PE3 and PE4-PE6, display high and persistent bactericidal and bacteriostatic activity, comparable to PE embedded with AgNO 3 . By contrast, composites PE7-PE9 exhibit a reduced antibacterial action. Contact and release tests in several conditions for specific migration of Ag + from plastics, indicate a very limited but time persistent release of silver ions from PE1-PE6 composites, thus suggesting that they are potential antibacterial materials for future applications. Instead, PE7-PE9 almost do not release silver, only trace levels of silver ions being detected, in accordance with their reduced antibacterial action. None of
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Structure and properties of polyethylene films used in heavy lift balloons
NASA Technical Reports Server (NTRS)
Khoury, F.; Crissman, J. M.; Fanconi, B. M.; Wagner, H. L.; Botz, L. H.
1985-01-01
The following features of five polyethylene films used by NASA in the construction of heavy lift balloons have been examined: molecular weight, molecular weight distribution, branching, melting behavior, density, surface texture, birefringence, orientation of crystalline regions, unlaxial deformation in the machine and transverse directions, and the effect of sample geometry and strain rate on deformation behavior. The goal of this exploratory study was to determine whether there are significant differences in any of the above mentioned features, or combination of features between the films. The acquisition of such information is a first step towards determining whether there are any specific correlations between film characteristics and the incidence of catastrophic failure of balloons during ascent through the troposphere. This exploratory study has resulted in the identification of similarities and differences between various features of the films.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-09
... Film, Sheet and Strip From India: Extension of Time Limit for Final Results of Countervailing Duty New... terephthalate film, sheet and strip from India for SRF Limited (SRF), covering the period January 1, 2009, through December 31, 2009. See Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-07
... DEPARTMENT OF COMMERCE International Trade Administration [A-533-824] Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in Part, of Antidumping Duty Administrative Review AGENCY... terephthalate film, sheet and strip from India covering the period July 1, 2009, through June 30, 2010. See...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-09
... Film, Sheet and Strip From India: Extension of Time Limit for Final Results of Antidumping Duty New... terephthalate film, sheet and strip from India for SRF Limited (SRF) covering the period July 1, 2009, through December 31, 2009. See Polyethylene Terephthalate Film, Sheet and Strip from India: Preliminary Results of...
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Ahmad, Nor Monica; Abdullah, Jaafar; Yusof, Nor Azah; Ab Rashid, Ahmad Hazri; Abd Rahman, Samsulida; Hasan, Md. Rakibul
2016-01-01
A phenolic biosensor based on a zirconium oxide/polyethylene glycol/tyrosinase composite film for the detection of phenolic compounds has been explored. The formation of the composite film was expected via electrostatic interaction between hexacetyltrimethylammonium bromide (CTAB), polyethylene glycol (PEG), and zirconium oxide nanoparticles casted on screen printed carbon electrode (SPCE). Herein, the electrode was treated by casting hexacetyltrimethylammonium bromide on SPCE to promote a positively charged surface. Later, zirconium oxide was mixed with polyethylene glycol and the mixture was dropped cast onto the positively charged SPCE/CTAB. Tyrosinase was further immobilized onto the modified SPCE. Characterization of the prepared nanocomposite film and the modified SPCE surface was investigated by scanning electron microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and Cyclic voltamogram (CV). The developed biosensor exhibits rapid response for less than 10 s. Two linear calibration curves towards phenol in the concentrations ranges of 0.075–10 µM and 10–55 µM with the detection limit of 0.034 µM were obtained. The biosensor shows high sensitivity and good storage stability for at least 30 days. PMID:27367738
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Ahmad, Nor Monica; Abdullah, Jaafar; Yusof, Nor Azah; Ab Rashid, Ahmad Hazri; Abd Rahman, Samsulida; Hasan, Md Rakibul
2016-06-29
A phenolic biosensor based on a zirconium oxide/polyethylene glycol/tyrosinase composite film for the detection of phenolic compounds has been explored. The formation of the composite film was expected via electrostatic interaction between hexacetyltrimethylammonium bromide (CTAB), polyethylene glycol (PEG), and zirconium oxide nanoparticles casted on screen printed carbon electrode (SPCE). Herein, the electrode was treated by casting hexacetyltrimethylammonium bromide on SPCE to promote a positively charged surface. Later, zirconium oxide was mixed with polyethylene glycol and the mixture was dropped cast onto the positively charged SPCE/CTAB. Tyrosinase was further immobilized onto the modified SPCE. Characterization of the prepared nanocomposite film and the modified SPCE surface was investigated by scanning electron microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and Cyclic voltamogram (CV). The developed biosensor exhibits rapid response for less than 10 s. Two linear calibration curves towards phenol in the concentrations ranges of 0.075-10 µM and 10-55 µM with the detection limit of 0.034 µM were obtained. The biosensor shows high sensitivity and good storage stability for at least 30 days.
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Zheng, Xiaoli; Xu, Qun
2010-07-29
In this work, we provided a comparison study of morphology and crystallization behavior of polyethylene (PE) and poly(ethylene oxide) (PEO) on single-walled carbon nanotubes (SWNTs) with assistance of supercritical CO(2). The resulting polymer/SWNT nanohybrids were characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectra, wide-angle X-ray diffraction, and differential scanning calorimetry. SWNT small bundles were decorated by PE lamellar crystals, forming nanohybrid "shish-kebab" (NHSK) structure, whereas SWNTs were only wrapped by a thin amorphous polymer coating in the case of PEO. The varying morphologies of the nanohybrids were found to depend on the molecular conformation and the interactions between polymer chains and SWNTs. Nonisothermal experiments showed that SWNTs provided heterogeneous nucleation sites for PE crystallization, while the NHSK structure hindered polymer chain diffusion and crystal growth. Also, SWNTs played antinucleation effect on PEO. In addition, the formation mechanism analysis indicated that PE chains preferred to form a homogeneous coating along the tube axis before proceeding to kebab crystal growth. The purpose of this work is to enlarge the area of theoretical understanding of introducing precisely hierarchical structures on carbon nanotubes, which are important for functional design in nanodevice applications.
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Thermal and catalytic degradation of high and low density polyethylene into fuel oil
DOE Office of Scientific and Technical Information (OSTI.GOV)
Uddin, Azhar; Koizumi, Kazuo; Sakata, Yusaku
1996-12-31
The degradation of four different types of polyethylene (PE) namely high density PE (HDPE), low density PE (LDPE), linear low density PE (LLDPE), and cross-linked PE (XLPE) was carried out at 430 {degrees}C by batch operation using silica-alumina as a solid acid catalyst and thermally without any catalyst. For thermal degradation, both HDPE and XLPE produced significant amount of wax-like compounds and the yield of liquid products were lower than that of LDPE and LLDPE. LDPE and LLDPE also produced small amount of wax-like compounds. Thus the structure of the degrading polymers influenced the product yields. The liquid products frommore » thermal degradation were broadly distributed in the carbon fraction of n-C{sub 5} to n-C{sub 25} (boiling point range, 36-405 C). With silica-alumina, the polyethylenes were converted to liquid products with high yields (77-83 wt%) and without any wax production. The liquid products were distributed in the range of n-C{sub 5} to n-C{sub 20} (Mostly C{sub 5}-C{sub 12}). Solid acid catalyst indiscriminately degraded the various types of polyethylene into light fuel oil. 5 refs., 4 figs., 1 tab.« less
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Kim, Hyung Kyu; Zhang, Gang; Nam, Changwoo; Chung, T C Mike
2015-12-04
This paper examines polymer film morphology and several important properties of polyethylene-graft-sulfonated polyarylene ether sulfone (PE-g-s-PAES) proton exchange membranes (PEMs) for direct methanol fuel cell applications. Due to the extreme surface energy differences between a semi-crystalline and hydrophobic PE backbone and several amorphous and hydrophilic s-PAES side chains, the PE-g-s-PAES membrane self-assembles into a unique morphology, with many proton conductive s-PAES channels embedded in the stable and tough PE matrix and a thin hydrophobic PE layer spontaneously formed on the membrane surfaces. In the bulk, these membranes show good mechanical properties (tensile strength >30 MPa, Young's modulus >1400 MPa) and low water swelling (λ < 15) even with high IEC >3 mmol/g in the s-PAES domains. On the surface, the thin hydrophobic and semi-crystalline PE layer shows some unusual barrier (protective) properties. In addition to exhibiting higher through-plane conductivity (up to 160 mS/cm) than in-plane conductivity, the PE surface layer minimizes methanol cross-over from anode to cathode with reduced fuel loss, and stops the HO• and HO₂• radicals, originally formed at the anode, entering into PEM matrix. Evidently, the thin PE surface layer provides a highly desirable protecting layer for PEMs to reduce fuel loss and increase chemical stability. Overall, the newly developed PE-g-s-PAES membranes offer a desirable set of PEM properties, including conductivity, selectivity, mechanical strength, stability, and cost-effectiveness for direct methanol fuel cell applications.
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Kim, Hyung Kyu; Zhang, Gang; Nam, Changwoo; Chung, T.C. Mike
2015-01-01
This paper examines polymer film morphology and several important properties of polyethylene-graft-sulfonated polyarylene ether sulfone (PE-g-s-PAES) proton exchange membranes (PEMs) for direct methanol fuel cell applications. Due to the extreme surface energy differences between a semi-crystalline and hydrophobic PE backbone and several amorphous and hydrophilic s-PAES side chains, the PE-g-s-PAES membrane self-assembles into a unique morphology, with many proton conductive s-PAES channels embedded in the stable and tough PE matrix and a thin hydrophobic PE layer spontaneously formed on the membrane surfaces. In the bulk, these membranes show good mechanical properties (tensile strength >30 MPa, Young’s modulus >1400 MPa) and low water swelling (λ < 15) even with high IEC >3 mmol/g in the s-PAES domains. On the surface, the thin hydrophobic and semi-crystalline PE layer shows some unusual barrier (protective) properties. In addition to exhibiting higher through-plane conductivity (up to 160 mS/cm) than in-plane conductivity, the PE surface layer minimizes methanol cross-over from anode to cathode with reduced fuel loss, and stops the HO• and HO2• radicals, originally formed at the anode, entering into PEM matrix. Evidently, the thin PE surface layer provides a highly desirable protecting layer for PEMs to reduce fuel loss and increase chemical stability. Overall, the newly developed PE-g-s-PAES membranes offer a desirable set of PEM properties, including conductivity, selectivity, mechanical strength, stability, and cost-effectiveness for direct methanol fuel cell applications. PMID:26690232
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Au-nanoparticles grafted on plasma treated PE
NASA Astrophysics Data System (ADS)
Švorčík, V.; Chaloupka, A.; Řezanka, P.; Slepička, P.; Kolská, Z.; Kasálková, N.; Hubáček, T.; Siegel, J.
2010-03-01
Polyethylene (PE) surface was treated with Ar plasma. Activated surface was grafted from methanol solution of 1,2-ethanedithiol. Then the sample was immersed into freshly prepared colloid solution of Au-nanoparticles. Finally Au layer was sputtered on the samples. Properties of the modified PE were studied using various methods: AFM, EPR, RBS and nanoindentation. It was shown that the plasma treatment results in degradation of polymer chain (AFM) and creation of free radicals by EPR. After grafting with dithiol, the concentration of free radicals declines. The presence of Au and S in the surface layer after the coating with Au-nanoparticles was proved by RBS. Plasma treatment changes PE surface morphology and increases surface roughness, too. Another significant change in surface morphology and roughness was observed after deposition of Au-nanoparticles. Nanoindentation measurements show that the grafting with Au-nanoparticles increases adhesion of subsequently sputtered Au layer.
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Piezoresistive effect observed in flexible amorphous carbon films
NASA Astrophysics Data System (ADS)
Wang, B.; Jiang, Y. C.; Zhao, R.; Liu, G. Z.; He, A. P.; Gao, J.
2018-05-01
Amorphous carbon (a-C) films, deposited on Si substrates at 500 °C, were transferred onto flexible polyethylene (PE) substrates by a lift-off method, which overcomes the limit of deposition temperature. After transferring, a-C films exhibited a large piezoresistive effect. Such flexible samples could detect the change of bending angle by attaching them onto Cu foils. The ratio of the bending and non-bending resistances reaches as large as ~27.8, which indicates a potential application as a pressure sensor. Also, the a-C/PE sample revealed an enhanced sensitivity to gas pressure compared with the a-C/Si one. By controlling the bending angle, the sensitivity range can be tuned to shift to a low- or high-pressure region. The fatigue test shows a less than 1% change in resistance after 10 000 bending cycles. Our work provides a route to prepare the flexible and piezoresistive carbon-based devices with high sensitivity, controllable pressure-sensing and high stability.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-10
... Film, Sheet, and Strip From Taiwan: Extension of Time Limit for Final Results of the Antidumping Duty... preliminary results of this review. See Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan... Results and to issue a post-preliminary analysis regarding whether to use an alternate cost methodology...
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Jung, Yong Chae; Muramatsu, Hiroyuki; Park, Ki Chul; Shimamoto, Daisuke; Kim, Jin Hee; Hayashi, Takuya; Song, Sung Moo; Kim, Yoong Ahm; Endo, Morinobu; Dresselhaus, Mildred S
2009-12-16
It is demonstrated that an optically transparent and electrically conductive polyethylene oxide (PEO) film is fabricated by the introduction of individualized single-walled carbon nanotubes (SWNTs). The incorporated SWNTs in the PEO film sustain their intrinsic electronic and optical properties and, in addition, the intrinsic properties of the polymer matrix are retained. The individualized SWNTs with smaller diameter provide high transmittance as well as good electrical conductivity in PEO films. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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NASA Astrophysics Data System (ADS)
He, Linghao; Zheng, Xiaoli; Xu, Qun; Chen, Zhimin; Fu, Jianwei
2012-03-01
Carbon nanotubes (CNTs) and graphene nanosheets, as one-dimensional and two-dimensional carbon-based nanomaterials respectively, have different abilities to induce the polymer crystallization. In this study, hybrid materials, polyethylene (PE) decorating on CNTs and graphene oxide (GO), were prepared by a facile and efficient method using supercritical carbon dioxide (SC CO2) as anti-solvent. And the morphology and crystallization behavior of PE on CNTs and GO were investigated by transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectra, wide angle X-ray diffraction, and differential scanning calorimetry. Although both CNTs and GO could act as nucleating agents to induce PE epitaxial growth, CNTs were decorated by PE lamellar crystals forming nanohybrid "shish-kebab" (NHSK) structure, whereas GO sheets were only decorated with petal-like PE crystals. The varying morphologies of the nanohybrids depend on the PE epitaxy and the interactions between polymer chains and substrates. High surface curvature and the perfect ordered crystal structure of CNTs make PE crystals periodically grow on CNTs. While PE crystals grow and form multiple orientation-lamellae on GO due to the lattice matching and complex interactions between PE chains and GO. In addition, our experimental results show an interesting and evident stratification phenomenon for the PE/GO hybrid material, implying that GO decorated by PE have a screening function for the solvents. We anticipate that this work can widen the area of functionalization of carbon-based nanomaterials with a controlled means by an environmentally benign method, which are important for the functional design in nanodevice applications.
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Sharma, Swati; Bhaskar, Nitu; Bose, Surjasarathi; Basu, Bikaramjit
2018-05-01
A major challenge for tissue engineering is to design and to develop a porous biocompatible scaffold, which can mimic the properties of natural tissue. As a first step towards this endeavour, we here demonstrate a distinct methodology in biomimetically synthesized porous high-density polyethylene scaffolds. Co-extrusion approach was adopted, whereby high-density polyethylene was melt mixed with polyethylene oxide to form an immiscible binary blend. Selective dissolution of polyethylene oxide from the biphasic system revealed droplet-matrix-type morphology. An attempt to stabilize such morphology against thermal and shear effects was made by the addition of polyethylene- grafted-maleic anhydride as a compatibilizer. A maximum ultimate tensile strength of 7 MPa and elastic modulus of 370 MPa were displayed by the high-density polyethylene/polyethylene oxide binary blend with 5% maleated polyethylene during uniaxial tensile loading. The cell culture experiments with murine myoblast C2C12 cell line indicated that compared to neat high-density polyethylene and high-density polyethylene/polyethylene oxide, the high-density polyethylene/polyethylene oxide with 5% polyethylene- grafted-maleic anhydride scaffold significantly increased muscle cell attachment and proliferation with distinct elongated threadlike appearance and highly stained nuclei, in vitro. This has been partly attributed to the change in surface wettability property with a reduced contact angle (∼72°) for 5% PE- g-MA blends. These findings suggest that the high-density polyethylene/polyethylene oxide with 5% polyethylene- grafted-maleic anhydride can be treated as a cell growth substrate in bioengineering applications.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-14
... Film, Sheet and Strip From the United Arab Emirates: Extension of Time Limit for Preliminary Results of... polyethylene terephthalate film, sheet and strip from the United Arab Emirates (UAE) for the period November 06... analysis of all information on the record, specifically considering the cost and affiliation issues in this...
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USDA-ARS?s Scientific Manuscript database
Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear low density poly (ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days du...
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Fleming, Oliver S; Kazarian, Sergei G
2004-04-01
Poly(ethylene terephthalate) (PET) film was exposed to supercritical (sc) CO(2) and confocal Raman microscopy was used to investigate the morphological changes induced. The study evaluates the use of oil and dry objectives in confocal mode to obtain depth profiles of PET film. These results were compared with the data obtained by mapping of the film cross-section. A significant gradient of degree of crystallinity normal to the surface of PET film down to 60 microm has been observed. The gradient of the degree of morphological changes are functions of exposure time and pressure.
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Anti-bacterial treatment of polyethylene by cold plasma for medical purposes.
Popelka, Anton; Novák, Igor; Lehocký, Marián; Chodák, Ivan; Sedliačik, Ján; Gajtanska, Milada; Sedliačiková, Mariana; Vesel, Alenka; Junkar, Ita; Kleinová, Angela; Spírková, Milena; Bílek, František
2012-01-13
Polyethylene (PE) is one of the most widely used polymers in many industrial applications. Biomedical uses seem to be attractive, with increasing interest. However, PE it prone to infections and its additional surface treatment is indispensable. An increase in resistance to infections can be achieved by treating PE surfaces with substances containing antibacterial groups such as triclosan (5-Chloro-2-(2,4-dichlorophenoxy)phenol) and chlorhexidine (1,1'-Hexamethylenebis[5-(4-chlorophenyl)biguanide]). This work has examined the impact of selected antibacterial substances immobilized on low-density polyethylene (LDPE) via polyacrylic acid (PAA) grafted on LDPE by low-temperature barrier discharge plasma. This LDPE surface treatment led to inhibition of Escherichia coli and Staphylococcus aureus adhesion; the first causes intestinal disease, peritonitis, mastitis, pneumonia, septicemia, the latter is the reason for wound and urinary tract infections.
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Panseri, Sara; Chiesa, Luca Maria; Zecconi, Alfonso; Soncini, Gabriella; De Noni, Ivano
2014-06-25
Nowadays food wrapping assures attractive presentation and simplifies self-service shopping. Polyvinylchloride (PVC)- and polyethylene (PE)-based cling-films are widely used worldwide for wrapping cheeses. For this purpose, films used in retail possess suitable technical properties such as clinginess and unrolling capacity, that are achieved by using specific plasticizers during their manufacturing process. In the present study, the main VOCs of three cling-films (either PVC-based or PE-based) for retail use were characterized by means of Solid-Phase Micro-Extraction and GC/MS. In addition, the effects of cling film type and contact time on the migration of VOCs from the films to four different PDO Italian cheeses during cold storage under light or dark were also investigated. Among the VOCs isolated from cling-films, PVC released 2-ethylhexanol and triacetin. These compounds can likely be considered as a "non-intentionally added substance". These same compounds were also detected in cheeses wrapped in PVC films with the highest concentration found after 20 days storage. The PE cling-film was shown to possess a simpler VOC profile, lacking some molecules peculiar to PVC films. The same conclusions can be drawn for cheeses wrapped in the PE cling-film. Other VOCs found in wrapped cheeses were likely to have been released either by direct transfer from the materials used for the manufacture of cling-films or from contamination of the films. Overall, HS-SPME is shown to be a rapid and solvent free technique to screen the VOCs profile of cling-films, and to detect VOCs migration from cling-films to cheese under real retail storage conditions.
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NASA Technical Reports Server (NTRS)
2003-01-01
One of the most significant technical challenges in long-duration space missions is that of protecting the crew from harmful radiation. Protection against such radiation on a manned Mars mission will be of vital importance both during transit and while on the surface of the planet. The development of multifunctional materials that serve as integral structural members of the space vehicle and provide the necessary radiation shielding for the crew would be both mission enabling and cost effective. Additionally, combining shielding and structure could reduce total vehicle mass. Hybrid laminated composite materials having both ultramodulus polyethylene (PE) and graphite fibers in epoxy and PE matrices could meet such mission requirements. PE fibers have excellent physical properties, including the highest specific strength of any known fiber. Moreover, the high hydrogen (H) content of polyethylene makes the material an excellent shielding material for cosmic radiation. When such materials are incorporated into an epoxy or PE matrix a very effective shielding material is expected. Boron (B) may be added to the matrix resin or used as a coating to further increase the shielding effectiveness due to B s ability to slow thermal neutrons. These materials may also serve as micrometeorites shields due to PE s high impact energy absorption properties. It should be noted that such materials can be fabricated by existing equipment and methods. It is the objective of this work therefore to: (a) perform preliminary analysis of the radiation transport within these materials; (b) fabricate panels for mechanical property testing before and after radiation exposure. Preliminary determination on the effectiveness of the combinations of material components on both shielding and structural efficiency will be made.
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NASA Astrophysics Data System (ADS)
Adachi, Kazunari; Uchiyama, Kenta; Kuriyama, Takashi; Miyata, Ken; Hisamatsu, Tokuro
2009-11-01
The authors previously determined that thermal effects are not a dominant factor in the ultrasonic joining of very low density polyethylene (VLDPE) films using torsional vibration. Now, to confirm that the plastic materials are not “melted” by mechanically generated heat in the joining, they have conducted joining experiments for thin poly(ethylene terephthalate) (PET) films. The temperature at the interface of two PET films of 0.1 mm thickness only increased to approximately 100 °C, and no trace of liquidation of the material was observed at the interface under a polarizing microscope. Investigation using a differential scanning calorimeter (DSC) revealed that the “melting point” of PET is about 260 °C, and an ultrasonically joined specimen showed no significant difference in thermal characteristics compared with an intact PET film. It was also determined that the PET films cannot be joined even after being pressed together for a period of 30 min or longer at approximately 150 °C. From the results obtained using the microscope and the DSC, the authors conclude that melting of the materials plays essentially no role in ultrasonic plastic joining.
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Metal adsorption of gamma-irradiated carboxymethyl cellulose/polyethylene oxide blend films
NASA Astrophysics Data System (ADS)
El-Naggar, Amal A.; Magida, M. M.; Ibrahim, Sayeda M.
2016-03-01
Blend films of different ratios of carboxymethyl cellulose (CMC)/polyethylene oxide (PEO) were prepared by the solution casting method. To investigate the effect of irradiation on all properties of prepared blend, it was exposed to different gamma irradiation doses (10, 20, and 30 kGy). Physical properties such as gel fraction (GF) (%) and swelling (SW) (%) were investigated. It was found that the GF (%) increases with increasing irradiation dose up to 20 kGy, while SW (%) decreases with an increase in the irradiation doses for all blend compositions. Moreover, the structural and mechanical properties of the prepared films were studied. The results of the mechanical properties obtained showed that there is an improvement in these properties with an increase in both CMC and irradiation dose up to 20 kGy. The efficiency of metal ions uptake was measured using a UV spectrophotometer. The prepared films showed good tendency to absorb and release metal ions from aqueous media. Thus, the CMC/PEO film can be used in agricultural domain.
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Modeling uptake of hydrophobic organic contaminants into polyethylene passive samplers.
Thompson, Jay M; Hsieh, Ching-Hong; Luthy, Richard G
2015-02-17
Single-phase passive samplers are gaining acceptance as a method to measure hydrophobic organic contaminant (HOC) concentration in water. Although the relationship between the HOC concentration in water and passive sampler is linear at equilibrium, mass transfer models are needed for nonequilibrium conditions. We report measurements of organochlorine pesticide diffusion and partition coefficients with respect to polyethylene (PE), and present a Fickian approach to modeling HOC uptake by PE in aqueous systems. The model is an analytic solution to Fick's second law applied through an aqueous diffusive boundary layer and a polyethylene layer. Comparisons of the model with existing methods indicate agreement at appropriate boundary conditions. Laboratory release experiments on the organochlorine pesticides DDT, DDE, DDD, and chlordane in well-mixed slurries support the model's applicability to aqueous systems. In general, the advantage of the model is its application in the cases of well-agitated systems, low values of polyethylene-water partioning coefficients, thick polyethylene relative to the boundary layer thickness, and/or short exposure times. Another significant advantage is the ability to estimate, or at least bound, the needed exposure time to reach a desired CPE without empirical model inputs. A further finding of this work is that polyethylene diffusivity does not vary by transport direction through the sampler thickness.
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Affatato, Saverio; De Mattia, Jonathan Salvatore; Bracco, Pierangiola; Pavoni, Eleonora; Taddei, Paola
2016-06-01
First-generation (irradiated and remelted or annealed) and second-generation (irradiated and vitamin E blended or doped) highly crosslinked polyethylenes were introduced in the last decade to solve the problems of wear and osteolysis. In this study, the influence of the Vitamin-E addition on crosslinked polyethylene (XLPE_VE) was evaluated by comparing the in vitro wear behavior of crosslinked polyethylene (XLPE) versus Vitamin-E blended polyethylene XLPE and conventional ultra-high molecular weight polyethylene (STD_PE) acetabular cups, after accelerated ageing according to ASTM F2003-02 (70.0±0.1°C, pure oxygen at 5bar for 14 days). The test was performed using a hip joint simulator run for two millions cycles, under bovine calf serum as lubricant. Mass loss was found to decrease along the series XLPE_VE>STD_PE>XLPE, although no statistically significant differences were found between the mass losses of the three sets of cups. Micro-Raman spectroscopy was used to investigate at a molecular level the morphology changes induced by wear. The spectroscopic analyses showed that the accelerated ageing determined different wear mechanisms and molecular rearrangements during testing with regards to the changes in both the chain orientation and the distribution of the all-trans sequences within the orthorhombic, amorphous and third phases. The results of the present study showed that the addition of vitamin E was not effective to improve the gravimetric wear of PE after accelerated ageing. However, from a molecular point of view, the XLPE_VE acetabular cups tested after accelerated ageing appeared definitely less damaged than the STD_PE ones and comparable to XLPE samples. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Johnston, Brian; Jiang, Guozhan; Hill, David; Adamus, Grazyna; Kwiecień, Iwona; Zięba, Magdalena; Sikorska, Wanda; Green, Matthew; Kowalczuk, Marek; Radecka, Iza
2017-08-28
There is an increasing demand for bio-based polymers that are developed from recycled materials. The production of biodegradable polymers can include bio-technological (utilizing microorganisms or enzymes) or chemical synthesis procedures. This report demonstrates the corroboration of the molecular structure of polyhydroxyalkanoates (PHAs) obtained by the conversion of waste polyethylene (PE) via non-oxygenated PE wax (N-PEW) as an additional carbon source for a bacterial species. The N-PEW, obtained from a PE pyrolysis reaction, has been found to be a beneficial carbon source for PHA production with Cupriavidus necator H16. The production of the N-PEW is an alternative to oxidized polyethylene wax (O-PEW) (that has been used as a carbon source previously) as it is less time consuming to manufacture and offers fewer industrial applications. A range of molecular structural analytical techniques were performed on the PHAs obtained; which included nuclear magnetic resonance (NMR) and electrospray ionisation tandem mass spectrometry (ESI-MS/MS). Our study showed that the PHA formed from N-PEW contained 3-hydroxybutyrate (HB) with 11 mol% of 3-hydroxyvalerate (HV) units.
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Johnston, Brian; Jiang, Guozhan; Hill, David; Adamus, Grazyna; Zięba, Magdalena; Sikorska, Wanda; Green, Matthew; Kowalczuk, Marek
2017-01-01
There is an increasing demand for bio-based polymers that are developed from recycled materials. The production of biodegradable polymers can include bio-technological (utilizing microorganisms or enzymes) or chemical synthesis procedures. This report demonstrates the corroboration of the molecular structure of polyhydroxyalkanoates (PHAs) obtained by the conversion of waste polyethylene (PE) via non-oxygenated PE wax (N-PEW) as an additional carbon source for a bacterial species. The N-PEW, obtained from a PE pyrolysis reaction, has been found to be a beneficial carbon source for PHA production with Cupriavidus necator H16. The production of the N-PEW is an alternative to oxidized polyethylene wax (O-PEW) (that has been used as a carbon source previously) as it is less time consuming to manufacture and offers fewer industrial applications. A range of molecular structural analytical techniques were performed on the PHAs obtained; which included nuclear magnetic resonance (NMR) and electrospray ionisation tandem mass spectrometry (ESI-MS/MS). Our study showed that the PHA formed from N-PEW contained 3-hydroxybutyrate (HB) with 11 mol% of 3-hydroxyvalerate (HV) units. PMID:28952552
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Fumigation efficacy and emission reduction using low-permeability film in orchard soil fumigation.
Gao, Suduan; Sosnoskie, Lynn M; Cabrera, Jose Alfonso; Qin, Ruijun; Hanson, Bradley D; Gerik, James S; Wang, Dong; Browne, Greg T; Thomas, John E
2016-02-01
Many orchards use fumigation to control soilborne pests prior to replanting. Controlling emissions is mandatory to reduce air pollution in California. This research evaluated the effects of plastic film type [polyethylene (PE) or totally impermeable film (TIF)], application rate of Telone C35 [full (610 kg ha(-1) ), 2/3 or 1/3 rates] and carbonation at 207 kPa on fumigant transport (emission and in soil) and efficacy. While increasing fumigant concentrations under the tarp, TIF reduced emissions >95% (∼2% and <1% of total applied 1,3-dichloropropene and chloropicrin respectively) relative to bare soil, compared with ∼30% reduction by PE. All fumigation treatments, regardless of film type, provided good nematode control above 100 cm soil depth; however, nematode survival was high at deeper depths. Weed emergence was mostly affected by tarping and fumigant rate, with no effects from the carbonation. TIF can effectively reduce fumigant emissions. Carbonation under the studied conditions did not improve fumigant dispersion and pest control. The 2/3 rate with TIF controlled nematodes as effectively as the full rate in bare soil or under the PE film to 100 cm soil depth. However, control of nematodes in deeper soil remains a challenge for perennial crops. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.
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Li, Hui; Li, Wei; Li, Shuhua; Ma, Jing
2008-06-12
Molecular fragmentation quantum mechanics (QM) calculations have been combined with molecular mechanics (MM) to construct the fragmentation QM/MM method for simulations of dilute solutions of macromolecules. We adopt the electrostatics embedding QM/MM model, where the low-cost generalized energy-based fragmentation calculations are employed for the QM part. Conformation energy calculations, geometry optimizations, and Born-Oppenheimer molecular dynamics simulations of poly(ethylene oxide), PEO(n) (n = 6-20), and polyethylene, PE(n) ( n = 9-30), in aqueous solution have been performed within the framework of both fragmentation and conventional QM/MM methods. The intermolecular hydrogen bonding and chain configurations obtained from the fragmentation QM/MM simulations are consistent with the conventional QM/MM method. The length dependence of chain conformations and dynamics of PEO and PE oligomers in aqueous solutions is also investigated through the fragmentation QM/MM molecular dynamics simulations.
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Moez, A Abdel; Aly, S S; Elshaer, Y H
2012-07-01
The low density polyethylene (LDPE) films were irradiated with gamma radiation in the dose range varied from 20 to 400 kGy. The induced changes in the chemical structure and dielectric properties for the irradiated films were investigated. The structure modifications: crystallinity as well as possible molecular changes of the polymer were recognized using Fourier Transform Infrared Spectroscopy (FTIR). The optical results were determined from transmission, reflection and absorption spectra for these films. The dielectric properties of these films were calculated using optical methods. Result indicates small variation in crystallinity which could be increased or decreased depending on the relative importance of the structural and chemical changes. Copyright © 2012 Elsevier B.V. All rights reserved.
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Desai, N P; Hubbell, J A
1992-01-01
Polyethylene terephthalate films surface modified with polyethylene oxide of mol wt 18,500 g/mol (18.5 k) by a previously described technique, were implanted in the peritoneal cavity of mice, along with their respective untreated controls, for periods of 1-28 d. The implants were retrieved and examined for tissue reactivity and cellular adherence. The control polyethylene terephthalate surfaces showed an initial inflammatory reaction followed by an extensive fibrotic response with a mean thickness of 60 microns at 28 d. By contrast, polyethylene oxide-modified polyethylene terephthalate showed only a mild inflammatory response and no fibrotic encapsulation throughout the implantation period: at 28 d a cellular monolayer was observed. Apparently either the polyethylene oxide-modified surface was stimulating less inflammation, which was in turn stimulating less fibroblastic overgrowth, or the cellular adhesion to the polyethylene oxide-modified surface was too weak to support cellular multilayers.
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Effect of [gamma]-irradiation on latent tracks of polyethylene terephthalate (PET) film
NASA Astrophysics Data System (ADS)
Hiroki, A.; Asano, M.; Yamaki, T.; Yoshida, M.
2005-04-01
The pre-treatment effect of γ-irradiation on latent tracks of polyethylene terephthalate (PET) films bombarded with swift heavy ions was investigated by electric conductometry and scanning electron microscope (SEM) observation. The Xe-ion bombarded PET films were etched for 6 h in 0.2 M NaOH aqueous solution at 70 °C to prepare track-etched membranes. As γ-irradiation doses increased in the range of 0-160 kGy, the surface pore diameter obtained by SEM observation decreased while that obtained by conductometry became large. This inconsistent result between the two methods was due to an increase in the crosslinked region in the latent tracks caused by γ-irradiation.
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Grieco, E M; Baldi, G
2012-05-01
In the present study the interactions between the main constituents of the refuse derived fuel (plastics, paper, and wood) during pyrolysis were studied. Binary mixtures of polyethylene-paper and polyethylene/sawdust have been transformed into pellets and pyrolyzed. Various mixtures with different composition were analyzed and pyrolysis products (tar, gas, and char) were collected. The mixtures of wood/PE and paper/PE have a different behavior. The wood/PE mixtures showed a much reduced interaction of the various compounds because the yields of pyrolysis products of the mixture can be predicted as linear combination of those of the pure components. On the contrary, a strong char yield increase was found at a low heating rate for paper/PE mixtures. In order to explain the results, the ability of wood and paper char to adsorb and convert the products of PE pyrolysis into was studied. Adsorption and desorption tests were performed on the char obtained by paper and wood by using n-hexadecane as a model compound for the heavy products of PE pyrolysis. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Effects of packaging materials on storage quality of peanut kernels
Fu, Xiaoji; Xing, Shengping; Xiong, Huiwei; Min, Hua; Zhu, Xuejing; He, Jialin; Mu, Honglei
2018-01-01
In order to obtain optimum packaging materials for peanut kernels, the effects of four types of packaging materials on peanut storage quality (coat color, acid value, germination rate, relative damage, and prevention of aflatoxin contamination) were examined. The results showed that packaging materials had a major influence on peanut storage quality indexes. The color of the peanut seed coat packaged in the polyester/aluminum/polyamide/polyethylene (PET/AL/PA/PE) composite film bag did not change significantly during the storage period. Color deterioration was slower with polyamide/polyethylene (PA/PE) packaging materials than with polyethylene (PE) film bags and was slower in PE bags than in the woven bags. The use of PET/AL/PA/PE and PA/PE bags maintained peanut quality and freshness for more than one year and both package types resulted in better germination rates. There were significant differences between the four types of packaging materials in terms of controlling insect pests. The peanuts packaged in the highly permeable woven bags suffered serious invasion from insect pests, while both PET/AL/PA/PE and PA/PE bags effectively prevented insect infection. Peanuts stored in PET/AL/PA/PE and PA/PE bags were also better at preventing and controlling aflatoxin contamination. PMID:29518085
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Radiative human body cooling by nanoporous polyethylene textile.
Hsu, Po-Chun; Song, Alex Y; Catrysse, Peter B; Liu, Chong; Peng, Yucan; Xie, Jin; Fan, Shanhui; Cui, Yi
2016-09-02
Thermal management through personal heating and cooling is a strategy by which to expand indoor temperature setpoint range for large energy saving. We show that nanoporous polyethylene (nanoPE) is transparent to mid-infrared human body radiation but opaque to visible light because of the pore size distribution (50 to 1000 nanometers). We processed the material to develop a textile that promotes effective radiative cooling while still having sufficient air permeability, water-wicking rate, and mechanical strength for wearability. We developed a device to simulate skin temperature that shows temperatures 2.7° and 2.0°C lower when covered with nanoPE cloth and with processed nanoPE cloth, respectively, than when covered with cotton. Our processed nanoPE is an effective and scalable textile for personal thermal management. Copyright © 2016, American Association for the Advancement of Science.
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Tankhiwale, Rasika; Bajpai, S K
2012-02-01
The present work describes the preparation of ZnO nanoparticles loaded starch-coated polyethylene film. The presence of ZnO nanoparticles was confirmed by surface plasmon resonance (SPR), X-ray diffraction (XRD) studies and transmission electron microscopy (TEM). The ZnO loaded film was tested for its biocidal action against model bacteria Escherichia coli using zone inhibition and killing kinetics of bacterial growth methods. This newly developed material bears potential to be used as food packaging material to prevent food stuff from bacterial contamination. Copyright © 2011 Elsevier B.V. All rights reserved.
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SECURING CONTAINERIZED HAZARDOUS WASTES WITH WELDED POLYETHYLENE ENCAPSULATES
Full-scale encapsulation of 208-liter (55-gal) drums was studied as a means for managing corroding containers of hazardous wastes in the field and rendering them suitable for transport and safe deposit within a final disposal site such as a landfill. Polyethylene (PE) receivers w...
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Novotná, Zdenka; Rimpelová, Silvie; Juřík, Petr; Veselý, Martin; Kolská, Zdenka; Hubáček, Tomáš; Ruml, Tomáš; Švorčík, Václav
2017-02-01
We have investigated the application of Ar plasma for creation of nanostructured ultra high molecular weight polyethylene (PE) surface in order to enhance adhesion of mouse embryonic fibroblasts (L929). The aim of this study was to investigate the effect of the interface between plasma-treated and gold-coated PE on adhesion and spreading of cells. The surface properties of pristine samples and its modified counterparts were studied by different experimental techniques (gravimetry, goniometry and X-ray photoelectron spectroscopy (XPS), electrokinetic analysis), which were used for characterization of treated and sputtered layers, polarity and surface chemical structure, respectively. Further, atomic force microscopy (AFM) was employed to study the surface morphology and roughness. Biological responses of cells seeded on PE samples were evaluated in terms of cell adhesion, spreading, morphology and proliferation. Detailed cell morphology and intercellular connections were followed by scanning electron microscopy (SEM). As it was expected the thickness of a deposited gold film was an increasing function of the sputtering time. Despite the fact that plasma treatment proceeded in inert plasma, oxidized degradation products were formed on the PE surface which would contribute to increased hydrophilicity (wettability) of the plasma treated polymer. The XPS method showed a decrease in carbon concentration with increasing plasma treatment. Cell adhesion measured on the interface between plasma treated and gold coated PE was inversely proportional to the thickness of a gold layer on a sample. Copyright © 2016. Published by Elsevier B.V.
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Simulated glass transition of poly(ethylene oxide) bulk and film: a comparative study.
Wu, Chaofu
2011-09-29
Stepwise cooling molecular dynamics (MD) simulations have been carried out on the bulk and film models for poly(ethylene oxide) (PEO) to understand glass transition of amorphous polymer films. Three types of properties--density, energy, and dynamics--are computed and plotted against the temperature for the two systems. It has been confirmed that all these properties can reveal glass transition in both PEO bulk and film systems. All the determined glass transition temperatures (T(g)'s) drop in the same order of magnitude to the experimental data available. Among various methods, the T(g)'s obtained from the density and energy data are close to each other if the same space regions are defined, which can suggest the same free volume theory, and dynamic T(g)'s obtained from mean-squared displacements (MSDs) are highest, which can suggest the kinetic theory for structural relaxation. Consistently, all these T(g)'s obtained using different methods show that the T(g)'s of PEO film are lower than those of PEO bulk. The free surface layers of polymer films dictate this offset. © 2011 American Chemical Society
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Adhesion Improvement between Polyethylene and Aluminum Using Eco-Friendly Plasma Treatment
NASA Astrophysics Data System (ADS)
Popelka, Anton; Krupa, Igor; Novák, Igor; Ouederni, Mabrouk; Abdulaqder, Fatima; Al-Yazedi, Shrooq; Al-Gunaid, Taghreed; Al-Senani, Thuraya
Polyethylene (PE) belongs among the most widely used polymers in many industrial applications, such as in building, packaging or transport industry. Qatar is one of the largest producers of PE in the world. Composite laminates consisting of PE and metal materials, such as aluminum (Al) lead to an improvement of various mechanical and physical properties necessary for special applications in building industry. Aluminum composite panel (ACP) represents type of flat panel that consists of two thin aluminum sheets bonded to a non-aluminum core, often made from PE. ACPs are frequently used for external cladding or facades of buildings. The main problem relates the adhesion between both materials. In this research work the improvement of adhesion properties of composite laminates prepared from PE and Al using plasma treatment was investigated. This surface treatment led to the significantly increase of peel strength of PE-Al adhesive joints.
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Lam, Jeun-Yan; Shih, Chien-Chung; Lee, Wen-Ya; Chueh, Chu-Chen; Jang, Guang-Way; Huang, Cheng-Jyun; Tung, Shih-Huang; Chen, Wen-Chang
2018-05-30
Exploiting biomass has raised great interest as an alternative to the fossil resources for environmental protection. In this respect, polyethylene furanoate (PEF), one of the bio-based polyesters, thus reveals a great potential to replace the commonly used polyethylene terephthalate (PET) on account of its better mechanical, gas barrier, and thermal properties. Herein, a bio-based, flexible, conductive film is successfully developed by coupling a PEF plastic substrate with silver nanowires (Ag NWs). Besides the appealing advantage of renewable biomass, PEF also exhibits a good transparency around 90% in the visible wavelength range, and its constituent polar furan moiety is revealed to enable an intense interaction with Ag NWs to largely enhance the adhesion of Ag NWs grown above, as exemplified by the superior bending and peeling durability than the currently prevailing PET substrate. Finally, the efficiency of conductive PEF/Ag NWs film in fabricating efficient flexible organic thin-film transistor and organic photovoltaic (OPV) is demonstrated. The OPV device achieves a power conversion efficiency of 6.7%, which is superior to the device based on ITO/PEN device, manifesting the promising merit of the bio-based PEF for flexible electronic applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Huang, Xiaohua
2013-01-01
The structural evolution of low-molecular-weight poly(ethylene oxide)-block-polystyrene (PEO-b-PS) diblock copolymer thin film with various initial film thicknesses on silicon substrate under thermal annealing was investigated by atomic force microscopy, optical microscopy, and contact angle measurement. At film thickness below half of the interlamellar spacing of the diblock copolymer (6.2 nm), the entire silicon is covered by a polymer brush with PEO blocks anchored on the Si substrate due to the substrate-induced effect. When the film is thicker than 6.2 nm, a dense polymer brush which is equal to half of an interlamellar layer was formed on the silicon, while the excess material dewet this layer to form droplets. The droplet surface was rich with PS block and the PEO block crystallized inside the bigger droplet to form spherulite. PMID:24302862
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Physical and biological treatments of polyethylene-rice starch plastic films.
el-Naggar, Manal M A; Farag, Magdy Gh
2010-04-15
This study aimed to produce an industrial applicable thermo-stable alpha-amylase from marine Bacillus amyloliquefaciens which isolated and selected according to its significant enzyme production. The effect of different pH values and temperatures on the bacterial growth and the enzyme production was estimated using an experimental statistical design; maximum amylase production and bacterial growth was obtained at pH 7.0 and 50 degrees C. Some biodegradable polyethylene rice starch plastic films (PERS-P) were manufactured using 0, 2.5, 5, 7.5 and 10% starch concentrations. The biodegradability (reduction in the plastic elongation%) was tested using the exposure to UV radiation at lambda(300-400 nm) (intensity of about 1000 W/m(2)) and the produced B. amyloliquefaciens thermo-stable alpha-amylase. A significant reduction in the elongation% of these biodegradable plastics was observed in both cases especially on testing the 10% PERS-P; they showed a reduction of 26% and 20%, respectively, compared to the untreated plastic films (180+/-5). 2009 Elsevier B.V. All rights reserved.
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21 CFR 172.260 - Oxidized polyethylene.
Code of Federal Regulations, 2013 CFR
2013-04-01
... FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.260 Oxidized polyethylene. Oxidized polyethylene may... by high temperature vapor pressure osmometry; contains a maximum of 5 percent by weight of total...
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21 CFR 172.260 - Oxidized polyethylene.
Code of Federal Regulations, 2011 CFR
2011-04-01
... FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.260 Oxidized polyethylene. Oxidized polyethylene may... by high temperature vapor pressure osmometry; contains a maximum of 5 percent by weight of total...
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21 CFR 172.260 - Oxidized polyethylene.
Code of Federal Regulations, 2012 CFR
2012-04-01
... FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.260 Oxidized polyethylene. Oxidized polyethylene may... by high temperature vapor pressure osmometry; contains a maximum of 5 percent by weight of total...
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Qin, Ruijun; Gao, Suduan; Ajwa, Husein; Sullivan, David; Wang, Dong; Hanson, Bradley D
2011-01-01
Preplant soil fumigation is an important pest management practice in coastal California strawberry production regions. Potential atmospheric emissions of fumigants from field treatment, however, have drawn intensive environmental and human health concerns; increasingly stringent regulations on fumigant use have spurred research on low-emission application techniques. The objectives of this research were to determine the effects of a new low-permeability film, commonly known as totally impermeable film (TIF), on fumigant emissions and on fumigant distribution in soil. A 50/50 mixture of 1,3-dichloropropene (1,3-D) and chloropicrin (CP) was shank-applied at 314 kg ha in two location-separate field plots (0.4 ha each) in Ventura County, California, in fall 2009. One plot was surface-covered with standard polyethylene (PE) film, and the other was covered with TIF immediately after fumigant application. Data collection included emissions, soil-gas phase concentration profile, air concentration under the film, and soil residuals of the applied fumigants. Peak emission flux of 1,3-D and CP from the TIF field was substantially lower than from the PE field. Total through-film emission loss was 2% for 1,3-D and <1% for CP from the TIF field during a 6-d film covering period, compared with 43% for 1,3-D and 12% for CP from the PE field. However, on film-cutting, greater retention of 1,3-D in the TIF field resulted in a much higher emission surge compared with the PE field, while CP emissions were fairly low in both fields. Higher concentrations and a more uniform distribution in the soil profile for 1,3-D and CP were observed under the TIF compared with the PE film, suggesting that the TIF may allow growers to achieve satisfactory pest control with lower fumigant rates. The surging 1,3-D emissions after film-cutting could result in high exposure risks to workers and bystanders and must be addressed with additional mitigation measures. Copyright © by the American Society of
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Nikezic, D; Shahmohammadi Beni, Mehrdad; Krstic, D; Yu, K N
2016-01-01
Monte Carlo method has been used to determine the efficiency for proton production and to study the energy and angular distributions of the generated protons. The ENDF library of cross sections is used to simulate the interactions between the neutrons and the atoms in a polyethylene (PE) layer, while the ranges of protons with different energies in PE are determined using the Stopping and Range of Ions in Matter (SRIM) computer code. The efficiency of proton production increases with the PE layer thickness. However the proton escaping from a certain polyethylene volume is highly dependent on the neutron energy and target thickness, except for a very thin PE layer. The energy and angular distributions of protons are also estimated in the present paper, showing that, for the range of energy and thickness considered, the proton flux escaping is dependent on the PE layer thickness, with the presence of an optimal thickness for a fixed primary neutron energy.
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Nikezic, D.; Shahmohammadi Beni, Mehrdad; Krstic, D.; Yu, K. N.
2016-01-01
Monte Carlo method has been used to determine the efficiency for proton production and to study the energy and angular distributions of the generated protons. The ENDF library of cross sections is used to simulate the interactions between the neutrons and the atoms in a polyethylene (PE) layer, while the ranges of protons with different energies in PE are determined using the Stopping and Range of Ions in Matter (SRIM) computer code. The efficiency of proton production increases with the PE layer thickness. However the proton escaping from a certain polyethylene volume is highly dependent on the neutron energy and target thickness, except for a very thin PE layer. The energy and angular distributions of protons are also estimated in the present paper, showing that, for the range of energy and thickness considered, the proton flux escaping is dependent on the PE layer thickness, with the presence of an optimal thickness for a fixed primary neutron energy. PMID:27362656
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NASA Astrophysics Data System (ADS)
Xu, Zh. H.; Kong, Zh. N.
2014-07-01
Natural rubber (NR) and polyethylene (PE) composites were compounded with chemically treated coir fibers by using a heated two-roll mill. Two chemical treatments of the fibers — by silane and sodium hydroxide — were carried out to improve the interfacial adhesion between them and the polyethylene matrix. The mechanical properties of the composites obtained were evaluated and compared with those made from a neat polymer and untreated fibers. The mechanical properties of the composites, such as the tensile strength, Young's modulus, and the elongation at break, were examined, and their shrinkage and flame retardant characteristics were measured. From these experiments, the effect of plasma treatment on the mechanical-physical behavior of coconut-fiberreinforced NR/PE composites was identified. In addition, their thermal characteristics were evaluated, and the results showed a slight decrease in them with increasing content of coir fibers.
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NASA Astrophysics Data System (ADS)
Rizvi, Reza; Kim, Jae-Kyung; Naguib, Hani
2009-10-01
This study details the synthesis and characterization of novel porous composites of low density polyethylene (PE) and multiwalled carbon nanotubes (MWNT). PE-MWNT composites were prepared by melt blending the components in a twin screw compounder and porous structures were produced by a batch technique using CO2 as the solvent. The composites were characterized for dispersion using scanning electron microscopy and transmission electron microscopy; the results indicate a finely dispersed MWNT phase in PE. Thermal, rheological, electrical and mechanical properties of the composites were characterized and results indicate an electrical and rheological percolation threshold concentration of between 1 and 2 wt% MWNT in PE. Substantial improvements in the mechanical and electrical properties of PE were observed with the addition of 5 wt% MWNT. The porous PE-MWNT composites fabricated in this study were found to be conductive and have potential applications as anti-static materials for electrostatic discharge prevention.
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Antibacterial Performance of Alginic Acid Coating on Polyethylene Film
Karbassi, Elika; Asadinezhad, Ahmad; Lehocký, Marian; Humpolíček, Petr; Vesel, Alenka; Novák, Igor; Sáha, Petr
2014-01-01
Alginic acid coated polyethylene films were examined in terms of surface properties and bacteriostatic performance against two most representative bacterial strains, that is, Escherichia coli and Staphylococcus aureus. Microwave plasma treatment followed by brush formation in vapor state from three distinguished precursors (allylalcohol, allylamine, hydroxyethyl methacrylate) was carried out to deposit alginic acid on the substrate. Surface analyses via various techniques established that alginic acid was immobilized onto the surface where grafting (brush) chemistry influenced the amount of alginic acid coated. Moreover, alginic acid was found to be capable of bacterial growth inhibition which itself was significantly affected by the brush type. The polyanionic character of alginic acid as a carbohydrate polymer was assumed to play the pivotal role in antibacterial activity. The cell wall composition of two bacterial strains along with the substrates physicochemical properties accounted for different levels of bacteriostatic performance. PMID:25196604
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NASA Astrophysics Data System (ADS)
Nho, Young-Chang; Sohn, Joon-Yong; Shin, Junhwa; Park, Jong-Seok; Lim, Yoon-Mook; Kang, Phil-Hyun
2017-03-01
Although micro-porous membranes made of polyethylene (PE) offer excellent mechanical strength and chemical stability, they exhibit large thermal shrinkage at high temperature, which causes a short circuit between positive and negative electrodes in cases of unusual heat generation. We tried to develop a new technology to reduce the thermal shrinkage of PE separators by introducing γ-Al2O3 particles treated with coupling agent on PE separators. Nanocomposite γ-Al2O3/PE separators were prepared by the dip coating of polyethylene(PE) separators in γ-Al2O3/poly(vinylidenefluoride-hexafluoropropylene) (PVDF-HFP)/crosslinker (1,3,5-trially-1,3,5-triazine-2,4,6(1 H,3 H,5 H)-trione (TTT) solution with humidity control followed by electron beam irradiation. γ-Al2O3/PVDF-HFP/TTT (95/5/2)-coated PE separator showed the highest electrolyte uptake (157%) and ionic conductivity (1.3 mS/cm). On the basis of the thermal shrinkage test, the nanocomposite γ-Al2O3/PE separators containing TTT irradiated by electron beam exhibited a higher thermal resistance. Moreover, a linear sweep voltammetry test showed that the irradiated nanocomposite γ-Al2O3/PE separators have electrochemical stabilities of up to 5.0 V. In a battery performance test, the coin cell assembled with γ-Al2O3/PVDF-HFP/TTT-coated PE separator showed excellent discharge cycle performance.
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Study on flavonoid migration from active low-density polyethylene film into aqueous food simulants.
Zhang, Shuangling; Zhao, Haiyan
2014-08-15
The migration of flavonoids from low-density polyethylene (LDPE) film (0.4%, w/w) to aqueous food simulants over 16 weeks at 0, 15, and 30 °C was investigated. The migration amount of total flavonoids was calculated based on the rutin contents determined by high-performance liquid chromatography (HPLC). Diffusion and partition coefficients, along with the activation energy (Ea) were calculated based on Fick's second law. The results showed that the migration of flavonoids was influenced by temperature, time and the simulants. The Ea values for flavonoid diffusion were 49.2, 55.9, and 25.8 kJ mol(-1) in distilled water, 4% acetic acid and 30% ethanol, respectively. This study indicated that the flavonoids in LDPE film easily migrated into food simulants; and this behaviour was related to the low Ea values of flavonoid diffusion, especially in ethanol at 0-30 °C, when the antioxidants were released from the film. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Majewsky, Marius; Bitter, Hajo; Eiche, Elisabeth; Horn, Harald
2016-10-15
Microplastics are increasingly detected in the environment and the consequences on water resources and ecosystems are not clear to date. The present study provides a cost-effective and straightforward method to determine the mass concentrations of polymer types using thermal analysis. Characteristic endothermic phase transition temperatures were determined for seven plastic polymer types using TGA-DSC. Based on that, extracts from wastewater samples were analyzed. Results showed that among the studied polymers, only PE and PP could be clearly identified, while the phase transition signals of the other polymers largely overlap each other. Subsequently, calibration curves were run for PE and PP for qualitative measurements. 240 and 1540mg/m(3) of solid material (12µm to 1mm) was extracted from two wastewater effluent samples of a municipal WWTP of which 34% (81mg/m(3)) and 17% (257mg/m(3)) could be assigned to PE, while PP was not detected in any of the samples. The presented application of TGA-DSC provides a complementary or alternative method to FT-IR analyses for the determination of PE and PP in environmental samples. Copyright © 2016 Elsevier B.V. All rights reserved.
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Barish, Jeffrey A; Goddard, Julie M
2011-01-01
Nonmigratory active packaging, in which bioactive components are tethered to the package, offers the potential to reduce the need for additives in food products while maintaining safety and quality. A challenge in developing nonmigratory active packaging materials is the loss of biomolecular activity that can occur when biomolecules are immobilized. In this work, we describe a method in which a biocompatible polymer (polyethylene glycol, PEG) is grafted from the surface of ozone-treated low-density polyethylene (LDPE) resulting in a surface functionalized polyethylene to which a range of amine-terminated bioactive molecules can be immobilized. Free radical graft polymerization is used to graft PEG onto the LDPE surface, followed by immobilization of ethylenediamine onto the PEG tether. Ethylenediamine was used to demonstrate that amine-terminated molecules could be covalently attached to the PEG-grafted film. Changes in surface chemistry and topography were measured by attenuated total reflectance Fourier transform infrared spectroscopy, contact angle, atomic force microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. We demonstrate the ability to graft PEG onto the surface of polymer packaging films by free radical graft polymerization, and to covalently link an amine-terminated molecule to the PEG tether, demonstrating that amine-terminated bioactive compounds (such as peptides, enzymes, and some antimicrobials) can be immobilized onto PEG-grafted LDPE in the development of nonmigratory active packaging. Nonmigratory active packaging offers the potential for improving food safety and quality while minimizing the migration of the active agent into food. In this paper, we describe a technique to modify polyethylene packaging films such that active agents can be covalently immobilized by a biocompatible tether. Such a technique can be adapted to a number of applications such as antimicrobial, antioxidant, or immobilized enzyme active
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Xu, Gang; Wang, Qunhui; Gu, Qingbao; Cao, Yunzhe; DU, Xiaoming; Li, Fasheng
2006-01-01
Low-density polyethylene (LDPE) film residues left in farmlands due to agricultural activities were extensively investigated to evaluate the present pollution situation by selecting the typical areas with LDPE film application, including Harbin, Baoding, and Handan of China. The survey results demonstrated that the film residues were ubiquitous within the investigated areas and the amount reached 2,400-8,200 g ha(-1). Breakage rates of the film residues were almost at the same level in the studied fields. There were relatively small amounts of film residues remaining in neighboring farmland fields without application of LDPE film. The studies showed that the sheets of LDPE residues had the same oxidative deterioration, which was probably due to photodegradation instead of biodegradation. The higher molecular weight components of the LDPE film gradually decreased, which were reflected by the appearance of some small flakes detached from the film bodies. LDPE films in the investigated fields gradually deteriorated and the decomposing levels developed with their left time increasing. The degradation behaviors of LDPE films were confirmed by using Fourier transform infrared (FTIR), scanning electron microscopic (SEM), and gel permeation chromatography analyses.
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Improved self-healing of polyethylene/carbon black nanocomposites by their shape memory effect.
Wang, Xiaoyan; Zhao, Jun; Chen, Min; Ma, Lan; Zhao, Xiaodong; Dang, Zhi-Min; Wang, Zhenwen
2013-02-07
In this work, the improved self-healing of cross-linked polyethylene (PE) (cPE)/carbon black (CB) nanocomposites by their shape memory effect (SME) is investigated. CB nanoparticles are found to be homogeneously dispersed in the PE matrix and significantly increase the strength of the materials. Compared with the breaking of linear PE (lPE) at the melting temperature (T(m)), the cPE and cPE/CB nanocomposites still have high strength above T(m) due to the formation of networks. The cPE and cPE/CB nanocomposites show both high strain fixity ratio (R(f)) and high strain recovery ratio (R(r)). Crystallization-induced elongation is observed for all the prepared shape memory polymer (SMP) materials and the effect becomes less remarkable with increasing volume fraction of CB nanoparticles (v(CB)). The scratch self-healing tests show that the cross-linking of PE matrix, the addition of CB nanoparticles, and the previous stretching in the direction perpendicular to the scratch favor the closure of the scratch and its complete healing. This SME-aided self-healing could have potential applications in diverse fields such as coating and structure materials.
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Upadhyay, Rahul; Naskar, Sharmistha; Bhaskar, Nitu; Bose, Suryasarathi; Basu, Bikramjit
2016-05-18
The uniform dispersion of nanoparticles in a polymer matrix, together with an enhancement of interfacial adhesion is indispensable toward achieving better mechanical properties in the nanocomposites. In the context to biomedical applications, the type and amount of nanoparticles can potentially influence the biocompatibility. To address these issues, we prepared high-density polyethylene (HDPE) based composites reinforced with graphene oxide (GO) by melt mixing followed by compression molding. In an attempt to tailor the dispersion and to improve the interfacial adhesion, we immobilized polyethylene (PE) onto GO sheets by nucleophilic addition-elimination reaction. A good combination of yield strength (ca. 20 MPa), elastic modulus (ca. 600 MPa), and an outstanding elongation at failure (ca. 70%) were recorded with 3 wt % polyethylene grafted graphene oxide (PE-g-GO) reinforced HDPE composites. Considering the relevance of protein adsorption as a biophysical precursor to cell adhesion, the protein adsorption isotherms of bovine serum albumin (BSA) were determined to realize three times higher equilibrium constant (Keq) for PE-g-GO-reinforced HDPE composites as compared to GO-reinforced composites. To assess the cytocompatibility, we grew osteoblast cell line (MC3T3) and human mesenchymal stem cells (hMSCs) on HDPE/GO and HDPE/PE-g-GO composites, in vitro. The statistically significant increase in metabolically active cell over different time periods in culture for up to 6 days in MC3T3 and 7 days for hMSCs was observed, irrespective of the substrate composition. Such observation indicated that HDPE with GO or PE-g-GO addition (up to 3 wt %) can be used as cell growth substrate. The extensive proliferation of cells with oriented growth pattern also supported the fact that tailored GO addition can support cellular functionality in vitro. Taken together, the experimental results suggest that the PE-g-GO in HDPE can effectively be utilized to enhance both mechanical and
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Biodegradable Plastic Mulch Films: Impacts on Soil Microbial Communities and Ecosystem Functions.
Bandopadhyay, Sreejata; Martin-Closas, Lluis; Pelacho, Ana M; DeBruyn, Jennifer M
2018-01-01
Agricultural plastic mulch films are widely used in specialty crop production systems because of their agronomic benefits. Biodegradable plastic mulches (BDMs) offer an environmentally sustainable alternative to conventional polyethylene (PE) mulch. Unlike PE films, which need to be removed after use, BDMs are tilled into soil where they are expected to biodegrade. However, there remains considerable uncertainty about long-term impacts of BDM incorporation on soil ecosystems. BDMs potentially influence soil microbial communities in two ways: first, as a surface barrier prior to soil incorporation, indirectly affecting soil microclimate and atmosphere (similar to PE films) and second, after soil incorporation, as a direct input of physical fragments, which add carbon, microorganisms, additives, and adherent chemicals. This review summarizes the current literature on impacts of plastic mulches on soil biological and biogeochemical processes, with a special emphasis on BDMs. The combined findings indicated that when used as a surface barrier, plastic mulches altered soil microbial community composition and functioning via microclimate modification, though the nature of these alterations varied between studies. In addition, BDM incorporation into soil can result in enhanced microbial activity and enrichment of fungal taxa. This suggests that despite the fact that total carbon input from BDMs is minuscule, a stimulatory effect on microbial activity may ultimately affect soil organic matter dynamics. To address the current knowledge gaps, long term studies and a better understanding of impacts of BDMs on nutrient biogeochemistry are needed. These are critical to evaluating BDMs as they relate to soil health and agroecosystem sustainability.
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Biodegradable Plastic Mulch Films: Impacts on Soil Microbial Communities and Ecosystem Functions
Bandopadhyay, Sreejata; Martin-Closas, Lluis; Pelacho, Ana M.; DeBruyn, Jennifer M.
2018-01-01
Agricultural plastic mulch films are widely used in specialty crop production systems because of their agronomic benefits. Biodegradable plastic mulches (BDMs) offer an environmentally sustainable alternative to conventional polyethylene (PE) mulch. Unlike PE films, which need to be removed after use, BDMs are tilled into soil where they are expected to biodegrade. However, there remains considerable uncertainty about long-term impacts of BDM incorporation on soil ecosystems. BDMs potentially influence soil microbial communities in two ways: first, as a surface barrier prior to soil incorporation, indirectly affecting soil microclimate and atmosphere (similar to PE films) and second, after soil incorporation, as a direct input of physical fragments, which add carbon, microorganisms, additives, and adherent chemicals. This review summarizes the current literature on impacts of plastic mulches on soil biological and biogeochemical processes, with a special emphasis on BDMs. The combined findings indicated that when used as a surface barrier, plastic mulches altered soil microbial community composition and functioning via microclimate modification, though the nature of these alterations varied between studies. In addition, BDM incorporation into soil can result in enhanced microbial activity and enrichment of fungal taxa. This suggests that despite the fact that total carbon input from BDMs is minuscule, a stimulatory effect on microbial activity may ultimately affect soil organic matter dynamics. To address the current knowledge gaps, long term studies and a better understanding of impacts of BDMs on nutrient biogeochemistry are needed. These are critical to evaluating BDMs as they relate to soil health and agroecosystem sustainability. PMID:29755440
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Scarfato, P; Garofalo, E; Di Maio, L; Incarnato, L
2017-06-01
Transport, mechanical and global migration data concern multilayer food packaging films with different layouts, all incorporating a layered silicate/polyamide nanocomposite as oxygen barrier layer, and a low-density polyethylene (LDPE) as moisture resistant layer in direct contact with food. The data are related to "Tuning of co-extrusion processing conditions and film layout to optimize the performances of PA/PE multilayer nanocomposite films for food packaging" by Garofalo et al. (2017) [1]. Nanocomposite multilayer films, with different relative layer thicknesses and clay types, were produced using a laboratory scale co-extrusion blown-film equipment and were analyzed in terms of transport to oxygen and water vapor, mechanical properties and overall migration. The results have shown that all the multilayer hybrid films, based on the copolyamide layer filled with Cloisite 30B, displayed the most significant oxygen barrier improvements and the best mechanical properties compared to the unfilled films. No significant alteration of the overall migration values was observed, as expectable [2], [3], [4]. The performance improvement was more relevant in the case of the film with the thinner nanocomposite layer.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-15
... Antidumping Duty Changed Circumstances Review: Polyethylene Terephthalate Film, Sheet, and Strip From the... Saehan with regard to the antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET film) from Korea, effective as of the date of publication of this notice in the Federal Register...
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Conversion of post consumer polyethylene to the biodegradable polymer polyhydroxyalkanoate.
Guzik, Maciej W; Kenny, Shane T; Duane, Gearoid F; Casey, Eoin; Woods, Trevor; Babu, Ramesh P; Nikodinovic-Runic, Jasmina; Murray, Michael; O'Connor, Kevin E
2014-05-01
A process for the conversion of post consumer (agricultural) polyethylene (PE) waste to the biodegradable polymer medium chain length polyhydroxyalkanoate (mcl-PHA) is reported here. The thermal treatment of PE in the absence of air (pyrolysis) generated a complex mixture of low molecular weight paraffins with carbon chain lengths from C8 to C32 (PE pyrolysis wax). Several bacterial strains were able to grow and produce PHA from this PE pyrolysis wax. The addition of biosurfactant (rhamnolipids) allowed for greater bacterial growth and PHA accumulation of the tested strains. Some strains were only capable of growth and PHA accumulation in the presence of the biosurfactant. Pseudomonas aeruginosa PAO-1 accumulated the highest level of PHA with almost 25 % of the cell dry weight as PHA when supplied with the PE pyrolysis wax in the presence of rhamnolipids. The change of nitrogen source from ammonium chloride to ammonium nitrate resulted in faster bacterial growth and the earlier onset of PHA accumulation. To our knowledge, this is the first report where PE is used as a starting material for production of a biodegradable polymer.
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The sorption kinetics and isotherms of sulfamethoxazole with polyethylene microplastics.
Xu, Baile; Liu, Fei; Brookes, Philip C; Xu, Jianming
2018-06-01
Microplastics and sulfamethoxazole coexist ubiquitously in the marine environment, and microplastics tend to sorb organic pollutants from the surrounding environment. Here, the sorption kinetics and isotherms of sulfamethoxazole on polyethylene (PE) microplastics closely fitted a pseudo-second-order model (R 2 = 0.98) and linear model (R 2 = 0.99), respectively, indicating that the sorption process was partition-dominant interaction. The main binding mechanism was possibly the van der Waals interaction for hydrophilic sulfamethoxazole onto hydrophobic PE microplastics. The effects of pH, dissolved organic matter and salinity on sorption behavior were also studied. The sorption behavior of sulfamethoxazole on PE microplastics was not significantly influenced by pH and salinity, probably because the electrostatic repulsion played a minor role. In addition, the negligible effect of dissolved organic matter was attributed to the greater affinity of sulfamethoxazole to PE microplastics than to dissolved organic matter. Our results demonstrated that PE microplastics may serve as a carrier for sulfamethoxazole in the aquatic environment. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Preparation and release study of Triclosan in polyethylene/Triclosan anti-bacterial blend.
Kamalipour, Jamshid; Masoomi, Mahmood; Khonakdar, Hossein Ali; Razavi, Seyed Mohammad Reza
2016-09-01
In this study, medium density polyethylene (MDPE) incorporated with Triclosan antibacterial substance has been prepared and Triclosan release rate was investigated. The crystallinity level and matrix polarity, as two significant parameters in antibacterial release control, were studied. Triclosan, a well-established widespread antibacterial agent, was incorporated into medium density polyethylene (MDPE) and Maleic anhydride grafted polyethylene (PE-g-MA) was used to change the polarity of the MDPE matrix. A masterbatch of 10wt% Triclosan incorporated with the MDPE and various PE-g-MA concentrations were prepared using an internal mixer. Then the masterbatch was diluted in the MDPE matrix to produce compounds with 0.1, 0.5, and1wt% Triclosan via twin screw extruder. The compounds were molded by compression molding method and then were cooled in three different cooling rate methods: isothermal cooling (I), quenching (Q),and moderate 5-10°C/min cooling rate (M). Cooling rate effects on crystallinity level were investigated applying sample density measurement. UV-vis absorption spectroscopy was used to probe the release of Triclosan. Antibacterial properties of the compounds against Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus were measured. The results showed that by addition of PE-g-MA, Triclosan release rate was increased. It was confirmed that the sample crystallinity was decreased by the cooling rate enhancement. The results also showed that quenched samples indicated higher release of Triclosan. Cooling rate reduction and raising the polarity increased the release of Triclosan and improved the antibacterial properties of the compounds. Copyright © 2016 Elsevier B.V. All rights reserved.
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Patel, Rajkumar; Kim, Jinkyu; Lee, Chang Soo; Kim, Jong Hak
2014-12-01
We synthesized a novel polycarbonate Z-r-polyethylene glycol (PCZ-r-PEG) copolymer by solution polycondensation. Successful synthesis of PCZ-r-PEG copolymer was confirmed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H-NMR), gel permeation chromatography (GPC), and transmission electron microscopy (TEM). PCZ-r-PEG copolymer was used as a structure-directing agent for fabrication of mesoporous thin film containing a titanium dioxide (TiO2) layer. To control the porosity of the resultant inorganic layer, the ratio of titanium(IV) isopropoxide (TTIP) to PCZ-r-PEG copolymer was varied. The structure and porosity of the resulting mesoporous films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. Mesoporous TiO2 films fabricated on an F-doped tin oxide (FTO) surface were used as photoanodes for quasi-solid-state dye-sensitized solar cells (qssDSSCs). The highest efficiency achieved was 3.3% at 100 mW/cm2 for a film thickness of 750 nm, which is high considering the thickness of TiO2 film, indicating the importance of the structure-directing agent.
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Borreani, G; Tabacco, E
2014-01-01
This study examined the effect on the fermentation, chemical, and microbiological quality of corn silage covered with a new-generation high oxygen barrier film (HOB) made with a special grade of ethylene-vinyl alcohol (EVOH) compared with a standard polyethylene film (PE). Two bunkers (farms 1 and 2) were divided into 2 parts lengthwise so that half of the silo would be covered with PE film and the other with HOB film. Plastic net bags with fresh chopped corn were buried in the upper layer (close to and far from the wall) and in the central part of the bunkers. During spring-summer consumption, the bags were unloaded, weighed, and subsampled to analyze the dry matter (DM) content, neutral detergent fiber and starch contents, pH, lactic and monocarboxylic acids, yeast and mold counts, aerobic and anaerobic spore-former counts, and aerobic stability. We also determined the economic benefit of applying the novel covering. The top layer of silage conserved under the HOB film had a higher lactic acid content and lower pH; lower counts of yeasts, molds, and aerobic and anaerobic spore-formers; higher aerobic stability; and lower DM losses than the silage conserved under the PE film. The use of the HOB film prevented almost all of the silage in the upper layer from spoiling; only 2 out of 32 samples had a mold count >6log10 cfu/g. This led to a net economic gain when the HOB film was used on both farms due to the increased DM recovery and reduced labor time required to clean the upper layer, even though the HOB film cost about 2.3 times more than the PE film. Furthermore, use of the HOB film, which ensures a longer shelf life of silage during consumption, reduced the detrimental effect of yeasts, molds, and aerobic and anaerobic spore-formers on the nutritional and microbiological quality of the unloaded silage. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
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Morita, Daigo; Seki, Taisuke; Higuchi, Yoshitoshi; Takegami, Yasuhiko; Ishiguro, Naoki
2017-12-01
This study aimed at investigating differences in femoral head penetration between highly cross-linked polyethylene (HXLPE) cemented sockets and uncemented liners during 5 years postoperatively. Ninety-six patients (106 hips) with a mean age of 64.4 (range, 35-83) years underwent total hip arthroplasty using a HXLPE cemented socket or liner and were respectively divided into cemented (35 patients [37 hips]) and uncemented (61 patients [69 hips]) groups. Femoral head penetrations were evaluated on both anteroposterior (AP)-view and Lauenstein-view radiographs, and mean polyethylene (PE) wear rates were calculated based on femoral head penetration from 2 to 5 years. Multivariate analyses were performed to assess risk factors for PE wear. At 5 years postoperatively, the cemented and uncemented groups exhibited proximal direction femoral head penetrations of 0.103 mm and 0.124 mm (P = .226) and anterior direction penetrations of 0.090 mm and 0.151 mm (P = .002), respectively. The corresponding mean PE wear rates were 0.004 mm/y and 0.009 mm/y in the AP-view (P = .286) and 0.005 mm/y and 0.012 mm/y in the Lauenstein-view (P = .168), respectively. Left-side operation and high activity were independent risk factors for PE wear on AP-view. When HXLPE was used, all mean PE wear rates were very low and those of cemented sockets and uncemented liners were very similar. PE particle theory suggests that the occurrence of osteolysis and related aseptic loosening might consequently decrease. Copyright © 2017 Elsevier Inc. All rights reserved.
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Garrido-López, Alvaro; Esquiu, Vanesa; Tena, María Teresa
2007-05-25
Polymers require the use of some slip agents, such as oleamide and erucamide, in order to reduce their friction coefficient and to make films easier to handle. In this communication, three analytical methods consisting in pressurized liquid extraction (PLE) and gas chromatography (GC) are used to determine oleamide and erucamide in polyethylene films. The sample was extracted with pure isopropanol (two times) at 105 degrees C for 16 min. Then, the liquid extract containing oleamide and erucamide was analyzed by GC and three different detection systems: flame ionization detector (FID), thermoionic selective detector (TSD) and ion-trap mass spectrometry detector (MSD). Oleamide and erucamide were separated using a 30 m x 0.25 mm (I.D.) 5% phenyl-95% dimethyl-polysiloxane capillary column in 12 min. The chromatographic methods were characterized and compared in terms of repeatability, linearity and sensitivity. The GC-FID and GC-TSD methods were linear up to about 60 microg ml(-1), whereas the linear range for the GC-MSD method was shorter, from 20.5 to 42 microg ml(-1). LODs identified with GC-MSD were two times higher than those identified with the other two methods. Repeatability values (expressed as relative standard deviation) of less than 2.5% were found for FID and TSD but they were above 10% for MSD. Finally, each method was applied to determine the content of erucamide and oleamide in several polyethylene films and the results obtained were compared with those obtained from the nitrogen content measured by pyrolysis and gas-phase chemiluminescence. No significant differences were observed between the results of the methods.
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NASA Astrophysics Data System (ADS)
Kudoyarov, M. F.; Kozlovskii, M. A.; Patrova, M. Ya.; Potokin, I. L.; Ankudinov, A. V.
2016-07-01
The possibility of performing an energy-efficient variant of irradiation of 20-μm-thick polyethylene terephthalate films to obtain track membranes was considered. Irradiation was done on both sides of a film with a beam of 53.4-MeV Ar+8 ions having energy insufficient for a through track to be formed. The characteristics of the resulting track membrane samples were studied. It was found that these membranes can be used in some cases as a basis for fabrication of composite gas-separating membranes.
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Measurement of radon diffusion in polyethylene based on alpha detection
NASA Astrophysics Data System (ADS)
Rau, Wolfgang
2012-02-01
Radon diffusion in different materials has been measured in the past. Usually the diffusion measurements are based on a direct determination of the amount of radon that diffuses through a thin layer of material. Here we present a method based on the measurement of the radon daughter products which are deposited inside the material. Looking at the decay of 210Po allows us to directly measure the exponential diffusion profile characterized by the diffusion length. In addition we can determine the solubility of radon in PE. We also describe a second method to determine the diffusion constant based on the short-lived radon daughter products 218Po and 214Po, using the identical experimental setup. Measurements for regular polyethylene (PE) and High Molecular Weight Polyethylene (HMWPE) yielded diffusion lengths of (1.3±0.3) mm and (0.8±0.2) mm and solubilities of 0.5±0.1 and 0.7±0.2, respectively, for the first method; the diffusion lengths extracted from the second method are noticeably larger which may be caused by different experimental conditions during diffusion.
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Deng, Qian; Zhao, Yanyun
2011-04-01
Wine grape pomace (WGP) (cv. Merlot) extract-based films were studied in terms of their physicochemical, mechanical, water barrier, nutritional, and antibacterial properties. Pomace extract (PE) was obtained by hot water extraction and had a total soluble solid of 3.6% and pH 3.65. Plant-based polysaccharides, low methoxyl pectin (LMP, 0.75% w/w), sodium alginate (SA, 0.3% w/w), or Ticafilm (TF, 2% w/w), was added into PE for film formation, respectively. Elongation at break and tensile strength were 23% and 4.04 MPa for TF-PE film, 25% and 1.12 MPa for SA-PE film, and 9.89% and 1.56 MPa for LMP-PE film. Water vapor permeability of LMP-PE and SA-PE films was 63 and 60 g mm m(-2) d(-1) kPa, respectively, lower than that of TF-PE film (70 g mm m(-2) d(-1) kPa) (P<0.05). LMP-PE film had higher water solubility, indicated by the haze percentage of water after 24 h of film immersion (52.8%) than that of TF-PE (25.7%) and SA-PE (15.9%) films, and also had higher amount of released phenolics (96.6%) than that of TF-PE (93.8%) and SA-PE (80.5%) films. PE films showed antibacterial activity against both Escherichia coli and Listeria innocua, in which approximate 5-log reductions in E. coli and 1.7- to 3.0-log reductions in L. innocua were observed at the end of 24 h incubation test compared with control. This study demonstrated the possibility of utilizing WGP extracts as natural, antimicrobial, and antioxidant promoting film-forming material for various food applications. WGP extract-based edible films with the addition of a small amount of commercial polysaccharides showed attractive color and comparable mechanical and water barrier properties to other edible films. The films also demonstrated their potential antioxidant and antimicrobial functions. Hence, they may be used as colorful wraps or coatings for food, pharmaceutical, or other similar applications.
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UV induced surface modification on improving the cytocompatibility of metallocene polyethylene.
Jaganathan, Saravana K; Prasath, Mani M
2018-01-01
Demand for medical implants is rising day by day as the world becomes the place for more diseased and older people. Accordingly, in this research, metallocene polyethylene (mPE), a commonly used polymer was treated with UV rays for improving its biocompatibility. Scanning electron microscopy (SEM) images confirmed the formation of crests and troughs, which depicts the improvement of surface roughness of mPE substrates caused by UV etching. Accordingly, the contact angle measurements revealed that the wettability of mPE-2.5 J/cm2 (68.09º) and mPE-5 J/cm2 (57.93º) samples were found to be increased compared to untreated mPE (86.84º) indicating better hydrophilicity. Further, the UV treated surface exhibited enhanced blood compatibility as determined in APTT (untreated mPE- 55.3 ± 2.5 s, mPE-2.5 J/cm2 - 76.7 ± 4.1 s and mPE-5 J/cm2 - 112.3 ± 2 s) and PT (untreated mPE - 24.7 ± 1.5 s, mPE- 2.5 J/cm2 - 34.3 ± 1.1 s and mPE-5 J/cm2 - 43 ± 2 s) assay. Moreover, the treated mPE-2.5 J/cm2 (4.88%) and mPE-5 J/cm2 (1.79%) showed decreased hemolytic percentage compared to untreated mPE (15.40%) indicating better safety to red blood cells. Interestingly, the changes in physicochemical properties of mPE are directly proportional to the dosage of the UV rays. UV modified mPE surfaces were found to be more compatible as identified through MTT assay, photomicrograph and SEM images of the seeded 3T3 cell population. Hence UV-modified surface of mPE may be successfully exploited for medical implants.
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Malatray, Matthieu; Roux, Jean-Paul; Gunst, Stanislas; Pibarot, Vincent; Wegrzyn, Julien
2017-03-01
Dual mobility cup (DMC) consists of a cobalt-chromium (CoCr) alloy cup articulated with a polyethylene (PE) mobile component capturing the femoral head in force using a snap-fit technique. This biomechanical study was the first to evaluate and compare the generation of cracks in the retentive area of DMC mobile components made of highly crosslinked PE (XLPE) or conventional ultra-high molecular weight PE (UHMWPE). Eighty mobile components designed for a 52-mm diameter Symbol® DMC (Dedienne Santé, Mauguio, France) and a 28-mm diameter femoral head were analyzed. Four groups of 20 mobile components were constituted according to the PE material: raw UHMWPE, sterilized UHMWPE, annealed XLPE and remelted XLPE. Ten mobile components in each group were impacted with a 28-mm diameter CoCr femoral head using a snap-fit technique. The occurrence, location and area of the cracks in the retentive area were investigated using micro-CT (Skyscan 1176®, Bruker, Aarsellar, Belgium) with a 35 μm nominal isotropic voxel size by two observers blinded to the PE material and impaction or not of the mobile components. Compared to conventional UHMWPE, the femoral head snap-fit did not generate more or wider cracks in the retentive area of annealed or remelted XLPE mobile components. This biomechanical study suggests that XLPE in DMC could be a safe alternative to conventional UHMWPE regarding the generation of cracks in the retentive area related to the femoral head snap-fit.
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NASA Astrophysics Data System (ADS)
Han, Jin-Woo; Kang, Hee-Jin; Kim, Jong-Yeon; Kim, Gwi-Yeol; Seo, Dae-Shik
2006-12-01
In this study, inorganic multilayer thin-film encapsulation is adopted for the first time to protect an organic layer from moisture and oxygen. Inorganic multilayer thin-film encapsulation is deposited onto poly(ethylene terephthalate) (PET) using an electron beam and sputtering. The SiON/SiO2 and parylene layer show the most suitable properties. Under these conditions, the water vapor transmission rate (WVTR) for PET can be reduced from a level of 0.57 g m-2 day-1 (bare substrate) to 1× 10-5 g m-2 day-1 after the application of a SiON and SiO2 layer. These results indicate that PET/parylene/SiO2/SiON barrier coatings have high potential for flexible organic light-emitting diode (OLED) applications.
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Polyethylene nano crystalsomes formed at a curved liquid/liquid interface.
Wang, Wenda; Staub, Mark C; Zhou, Tian; Smith, Derrick M; Qi, Hao; Laird, Eric D; Cheng, Shan; Li, Christopher Y
2017-12-21
Crystallization is incommensurate with nanoscale curved space due to the lack of three dimensional translational symmetry of the latter. Herein, we report the formation of single-crystal-like, nanosized polyethylene (PE) capsules using a miniemulsion solution crystallization method. The miniemulsion was formed at elevated temperatures using PE organic solution as the oil phase and sodium dodecyl sulfate as the surfactant. Subsequently, cooling the system stepwisely for controlled crystallization led to the formation of hollow, nanosized PE crystalline capsules, which are named as crystalsomes since they mimic the classical self-assembled structures such as liposome, polymersome and colloidosome. We show that the formation of the nanosized PE crystalsomes is driven by controlled crystallization at the curved liquid/liquid interface of the miniemulson droplet. The morphology, structure and mechanical properties of the PE crystalsomes were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and atomic force spectroscopy. Electron diffraction showed the single-crystal-like nature of the crystalsomes. The incommensurateness between the nanocurved interface and the crystalline packing led to reduced crystallinity and crystallite size of the PE crystalsome, as observed from the X-ray diffraction measurements. Moreover, directly quenching the emulsion below the spinodal line led to the formation of hierarchical porous PE crystalsomes due to the coupling of the PE crystallization and liquid/liquid phase separation. We anticipate that this unique crystalsome represents a new type of nanostructure that might be used as nanodrug carriers and ultrasound contrast agents.
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Yoo, Joanne Y; Cai, Jenny; Chen, Antonia F; Austin, Matthew S; Sharkey, Peter F
2016-05-01
Some manufacturers have introduced polyethylene (PE) inserts in 1-mm increment thickness options to allow for finer adjustments in total knee arthroplasty kinematics. Two surgeons with extensive experience performed 88 total knee arthroplasties using implants with 1-mm PE inserts. After trial components were inserted and the optimal PE thickness was selected, the insert was removed and a trial insert size was randomly chosen from opaque envelopes (1-mm smaller, same size, and 1-mm larger). The knee was re-examined and the surgeon determined which size PE had been placed. Surgeons reliably determined insert thicknesses in 62.5% (55 of 88; P = .050) of trials. Surgeons were not able to accurately detect 1-mm incremental changes of trial PE implants on a consistent basis. The potential clinical usefulness of this concept should be further evaluated. Copyright © 2016 Elsevier Inc. All rights reserved.
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Kang, Sun-Chul; Kim, Min-Jeong; Choi, Ung-Kyu
2007-08-01
This study was conducted to investigate the antibacterial activity and shelf-life extension effect of iceberg lettuce packed in BN/PE film. The BN/PE film has a strong microbial suppression effect on pathogenic bacteria such as Escherichia coli, Salmonella enteritidis, and S. typhimurium. The number of psychrophiles and mesophiles during 5 days of cold storage of fresh-cut iceberg lettuce at 10 degrees C packaged in BN/PE film was strictly suppressed in comparison with other tested films (OPP, PE, and PET film). When fresh processed iceberg lettuce was processed and stored under the current conditions, the shelf-life of the product was longer than 5 days in the BN/PE film package, whereas the shelf-life when using the other films tested, PE, OPP and PET, was no longer than 3-4 days. The decay rates of the iceberg lettuce packed in the BN/PE film was maintained at 29.8 +/- 2.1% on the 5th day of preservation. The samples packed in BN/PE film maintained an excellent visual quality during the 3 days of storage without significant differences in comparison with the initial visual quality. No browning was observed in the samples packed in BN/PE film for up to 3 days. The texture of shredded iceberg lettuce packaged in BN/PE film remained unchanged up to 3 days, and then a moderate decrease in texture was observed after 4 days of storage. In addition, the overall acceptability of fresh-cut iceberg lettuce packaged in BN/PE film did not change for up to 3 days, whereas the samples packaged in the other films were inedible by 3 days of storage. In conclusion, the shelf-life of fresh-cut iceberg lettuce packaged in the BN/PE film was extended to more than 5 days at 10 degres C, whereas that in the other films was 2 days at 10 degrees C. Therefore, the shelf-life extension effect of the fresh-cut iceberg lettuce in BN/PE film packaging was very effective compared with the other films tested.
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Affatato, Saverio; De Mattia, Jonathan Salvatore; Bracco, Pierangiola; Pavoni, Eleonora; Taddei, Paola
2016-12-01
The objective of this study is to evaluate the effects of third-body particles on the in vitro wear behaviour of three different sets of polyethylene acetabular cups after prolonged testing in a hip simulator and accelerated ageing. Vitamin E-blended, cross-linked polyethylene (XLPE_VE), cross-linked polyethylene (XLPE) and conventional polyethylene (STD_PE) acetabular cups were simulator tested for two million cycles under severe conditions (i.e. by adding third-body particles to the bovine calf serum lubricant). Micro-Fourier Transform Infrared and micro-Raman spectroscopic analyses, differential scanning calorimetry, and crosslink density measurements were used to characterize the samples at a molecular level. The STD_PE cups had twice mass loss than the XLPE_VE components and four times than the XLPE samples; statistically significant differences were found between the mass losses of the three sets of cups. The observed wear trend was justified on the basis of the differences in cross-link density among the samples (XLPE>XLPE_VE>STD_PE). FTIR crystallinity profiles, bulk DSC crystallinity and surface micro-Raman crystallinity seemed to have a similar behaviour upon testing: all of them (as well as the all-trans and ortho-trans contents) revealed the most significant changes in XLPE and XLPE_VE samples. The more severe third-body wear testing conditions determined more noticeable changes in all spectroscopic markers with respect to previous tests. Unexpectedly, traces of bulk oxidation were found in both STD_PE (unirradiated) and XLPE (remelting-stabilized), which were expected to be stable to oxidation; on the contrary, XLPE_VE demonstrated a high oxidative stability in the present, highly demanding conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Slow crack growth test method for polyethylene gas pipes. Volume 1. Topical report, December 1992
DOE Office of Scientific and Technical Information (OSTI.GOV)
Leis, B.; Ahmad, J.; Forte, T.
1992-12-01
In spite of the excellent performance record of polyethylene (PE) pipes used for gas distribution, a small number of leaks occur in distribution systems each year because of slow growth of cracks through pipe walls. The Slow Crack Growth Test (SCG) has been developed as a key element in a methodology for the assessment of the performance of polyethylene gas distribution systems to resist such leaks. This tropical report describes work conducted in the first part of the research directed at the initial development of the SCG test, including a critical evaluation of the applicability of the SCG test asmore » an element in PE gas pipe system performance methodology. Results of extensive experiments and analysis are reported. The results show that the SCG test should be very useful in performance assessment.« less
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NASA Astrophysics Data System (ADS)
Kalinovskaya, I. V.; Zadorozhnaya, A. N.; Karasev, V. E.
2008-11-01
Polyethylene films activated with europium(III) complexes with carboxylic acids and Eu(L)3 · nD · xH2O + ANT compositions, where L is the trifluoroacetic, toluyl, or cinnamic acid anion and ANT is anthranilic acid, were prepared. The intensity of luminescence of the polymeric compositions depended on the content of luminophores (molar ratio between europium compounds and anthranilic acid). An analysis of the excitation spectra showed that, in polymer—Eu(L)3 · nPhen · xH2O + ANT compositions, there was effective energy transfer from phenanthroline to anthranilic acid levels.
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Su, Nan-Yao; Ban, Paul; Scheffrahn, Rudolf H
2004-04-01
Polyethylene film impregnated with lambda-cyhalothrin was placed over a sand plot and covered with a concrete slab to allow insecticide movement into the sand for a period of 5.5 yr. Discs of polyethylene film and sand beneath them were sampled annually for 5 yr and at 5.5 yr for bioassay with the Formosan and eastern subterranean termite. Results demonstrated that sufficient quantities of lambda-cyhalothrin were released from the impregnated polyethylene film into adjacent sand to prevent termite penetration. The impregnated film has less environmental impact than conventional liquid termiticides because the insecticide is held in the polymer. Other advantages include its dual function as a construction moisture barrier and ease in verifying its proper installation.
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NASA Astrophysics Data System (ADS)
Barsbay, Murat; Kavaklı, Pınar Akkaş; Güven, Olgun
2010-03-01
A novel polymeric ligand exchanger (PLE) was prepared for the removal of phosphate ions from water. 2,2'-dipyridylamine (DPA), a bidentate ligand forming compound with high coordination capacity with a variety of metal ions was bound to glycidyl methacrylate (GMA) grafted polypropylene/polyethylene (PP/PE) nonwoven fabric synthesized by radiation-induced grafting technique. DPA attachment on epoxy ring of GMA units was tested in different solvents, i.e. methanol, ethanol, dioxane and dimethylsulfoxide (DMSO). The highest amount of modification was achieved in dioxane. In order to prepare the corresponding PLE for the removal of phosphate, DPA-immobilized fabric was loaded with Cu(II) ions. Phosphate adsorption experiments were performed in batch mode at different pH (5-9) and phosphate concentrations. The fabric was found to be effective for the removal of phosphate ions. At every stage of preparation and use, the nonwoven fabric was characterized by thermal (i.e. DSC and TGA) and spectroscopic (FTIR) methods. Competitive adsorption experiments were also carried out using two solutions with different concentration levels at pH 7 to see the effect of competing ions. Phosphate adsorption was found to be effective and selective from solutions having trace amounts of competitive anions. It is expected that the novel PLE synthesized can be used for the removal of phosphate ions in low concentrations over a large range of pH.
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Stratification during evaporative assembly of multicomponent nanoparticle films
Liu, Xiao; Liu, Weiping; Carr, Amanda J.; ...
2018-01-03
Multicomponent coatings with layers comprising different functionalities are of interest for a variety of applications, including electronic devices, energy storage, and biomaterials. Rather than creating such a film using multiple deposition steps, we explore a single-step method to create such films by varying the particle Peclet numbers, Pe. Our hypothesis, based on recent theoretical descriptions of the stratification process, is that by varying particle size and evaporation rate such that Pe of large and small particles are above and below unity, we can create stratified films of polymeric and inorganic particles. In this paper, we present AFM on the surfacemore » composition of films comprising poly(styrene) nanoparticles (diameter 25–90 nm) and silica nanoparticles (diameter 8–14 nm). Previous studies on films containing both inorganic and polymeric particles correspond to large Pe values (e.g., 120–460), while we utilize Pe ~ 0.3–4, enabling us to test theories that have been developed for different regimes of Pe. We demonstrate evidence of stratification and effect of the Pe ratio, although our results agree only qualitatively with theory. Finally, our results also provide validation of recent theoretical descriptions of the film drying process that predict different regimes for large-on-top and small-on-top stratification.« less
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Stratification during evaporative assembly of multicomponent nanoparticle films
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Xiao; Liu, Weiping; Carr, Amanda J.
Multicomponent coatings with layers comprising different functionalities are of interest for a variety of applications, including electronic devices, energy storage, and biomaterials. Rather than creating such a film using multiple deposition steps, we explore a single-step method to create such films by varying the particle Peclet numbers, Pe. Our hypothesis, based on recent theoretical descriptions of the stratification process, is that by varying particle size and evaporation rate such that Pe of large and small particles are above and below unity, we can create stratified films of polymeric and inorganic particles. In this paper, we present AFM on the surfacemore » composition of films comprising poly(styrene) nanoparticles (diameter 25–90 nm) and silica nanoparticles (diameter 8–14 nm). Previous studies on films containing both inorganic and polymeric particles correspond to large Pe values (e.g., 120–460), while we utilize Pe ~ 0.3–4, enabling us to test theories that have been developed for different regimes of Pe. We demonstrate evidence of stratification and effect of the Pe ratio, although our results agree only qualitatively with theory. Finally, our results also provide validation of recent theoretical descriptions of the film drying process that predict different regimes for large-on-top and small-on-top stratification.« less
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NASA Astrophysics Data System (ADS)
Xu, Shunjian; Luo, Xiaorui; Xiao, Zonghu; Luo, Yongping; Zhong, Wei; Ou, Hui; Li, Yinshuai
2017-01-01
Polyethylene glycol (PEG) was employed as pore-forming agent to prepare TiO2 nanoporous film based on spin-coating a TiO2 nanoparticle mixed paste on fluorine doped tin oxide (FTO) glass. The electrochromic and optical properties of the obtained TiO2 film were investigated by cyclic voltammetry (CV), chronoamperometry (CA) and UV-Vis spectrophotometer. The results show that the PEG in the mixed paste endows the TiO2 film with well-developed porous structure and improves the uniformity of the TiO2 film, which are helpful for the rapid intercalation and extraction of lithium ions within the TiO2 film and the strengthening of the diffuse reflection of visible light in the TiO2 film. As a result, the TiO2 film derived from the mixed paste with PEG displays higher electrochemical activity and more excellent electrochromic performances compared with the TiO2 film derived from the mixed paste without PEG. The switching times of coloration/bleaching are respectively 10.16/5.65 and 12.77/6.13 s for the TiO2 films with PEG and without PEG. The maximum value of the optical contrast of the TiO2 film with PEG is 21.2% while that of the optical contrast of the TiO2 film without PEG is 14.9%. Furthermore, the TiO2 film with PEG has better stability of the colored state than the TiO2 film without PEG.
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UV Grafting Modification of Polyethylene Separator for Liion Battery
NASA Astrophysics Data System (ADS)
Lv, Xiaoyuan; Li, Hua; Zhang, Zhiqiang; Chang, Hiunam; Jiang, Li; Liu, Hezhou
Polyethylene (PE) separator was modified by UV grafting methyl acrylate (MA) and nano-SiO2 composite layer. The structure of functional group and morphology of the separator were analyzed by Fourier transform infrared spectrum (FT-IR) and scanning electron microscope (SEM). The wetting behavior and the heat resistance of the separator were also investigated by contact angle test and thermal shrinkage test respectively. The results show that MA/nano-SiO2 composite layer is successfully grafted onto the PE separator, and the addition of the DI water and butanol can make the nano-SiO2 dispersed better and lead to a microporous structure of the grafting layer. The grafted separator has a better wettability and heat resistance than the pristine one.
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Influence of ordering change on the optical and thermal properties of inflation polyethylene films
NASA Astrophysics Data System (ADS)
Morikawa, Junko; Orie, Akihiro; Hikima, Yuta; Hashimoto, Toshimasa; Juodkazis, Saulius
2011-04-01
Changes of thermal diffusivity inside femtosecond laser-structured volumes as small as few percent were reliably determined (with standard deviation less than 1%) with miniaturized sensors. An increase of thermal diffusivity of a crystalline high-density polyethylene (HDPE) inflation films by 10-20% from the measured (1.16 ± 0.01) × 10 -7 m 2 s -1 value in regions not structured by femtosecond laser pulses is considerably larger than that of non-crystalline polymers, 0-3%. The origin of the change of thermal diffusivity are interplay between the laser induced disordering, voids' formation, compaction, and changes in molecular orientation. It is shown that laser structuring can be used to modify thermal and optical properties. The birefringence and infrared spectroscopy with thermal imaging of CH 2 vibrations are confirming inter-relation between structural, optical, and thermal properties of the laser-structured crystalline HDPE inflation films. Birefringence modulation as high as Δ n ˜ ± 1 × 10 -3 is achieved with grating structures.
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Temperature increase and charging current in polyethylene film during application of high voltage
NASA Astrophysics Data System (ADS)
Zhang, Chao; Kaneko, Kazue; Mizutani, Teruyoshi
2001-12-01
Temperature increase in a low density polyethylene film during the application of high dc voltage was estimated by measuring the sound velocity with a pulsed electroacoustic method. The temperature shows no change under the electric field of 50 MVm-1 at ambient temperature of 30 °C. However, the temperature increases with time, and rises to 63.7 °C in 90 min of the voltage application at ambient temperature of 60 °C. The temperature increase was caused by Joule heating and it resulted in the increase of charging current during the application of high dc voltage. The increase in charging current calculated from the temperature increase agreed well with the experimental one.
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Zhiyong, Yu; Mielczarski, E; Mielczarski, J; Laub, D; Buffat, Ph; Klehm, U; Albers, P; Lee, K; Kulik, A; Kiwi-Minsker, L; Renken, A; Kiwi, J
2007-02-01
An innovative way to fix preformed nanocrystalline TiO(2) on low-density polyethylene film (LDPE-TiO(2)) is presented. The LDPE-TiO(2) film was able to mediate the complete photodiscoloration of Orange II using about seven times less catalyst than a TiO(2) suspension and proceeded with a photonic efficiency of approximately 0.02. The catalyst shows photostability over long operational periods during the photodiscoloration of the azo dye Orange II. The LDPE-TiO(2) catalyst leads to full dye discoloration under simulated solar light but only to a 30% TOC reduction since long-lived intermediates generated in solution seem to preclude full mineralization of the dye. Physical insight is provided into the mechanism of stabilization of the LDPE-TiO(2) composite during the photocatalytic process by X-ray photoelectron spectroscopy (XPS). The adherence of TiO(2) on LDPE is investigated by electron microscopy (EM) and atomic force microscopy (AFM). The thickness of the TiO(2) film is seen to vary between 1.25 and 1.69 microm for an unused LDPE-TiO(2) film and between 1.31 and 1.50 microm for a sample irradiated 10h during Orange II discoloration pointing out to a higher compactness of the TiO(2) film after the photocatalysis.
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NASA Astrophysics Data System (ADS)
Mehyar, G. F.; Bawab, A. Al
2015-10-01
Biodegradable packaging materials are degraded under the natural environmental conditions. Therefore using them could alleviate the problem of plastics accumulation in nature. For effective replacement of plastics, with biodegradable materials, biodegradable packages should keep their properties under the high relative humidity (RH) conditions. Therefore the objectives of the study were to develop biodegradable packaging material based on whey protein isolate (WPI) and pea starch (PS). To study their mechanical, oxygen barrier and solubility properties under different RHs compared with those of low density polyethylene (LDPE), the most used plastic in packaging. Films of WPI and PS were prepared separately and conditioned at different RH (30-90%) then their properties were studied. At low RHs (<50%), WPI films had 2-3 times lower elongation at break (E or stretchability) than PS and LDPE. Increasing RH to 90% significantly (P<0.01) increased the elongation of PS but not WPI and LDPE films. LDPE and WPI films kept significantly (P<0.01) higher tensile strength (TS) than PS films at high RH (90%). Oxygen permeability (OP) of all films was very low (<0.5 cm3 μm m-2 d-1 kPa-1) below 40% RH but increased for PS films and became significantly (P<0.01) different than that of LDPE and WPI at > 40% RH. Oxygen permeability of WPI and LDPE did not adversely affected by increasing RH to 65%. Furthermore, WPI and LDPE films had lower degree of hydration at 50% and 90% RH and total soluble matter than PS films. These results suggest that WPI could be successfully replacing LDPE in packaging of moist products.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Qiao, B.; Teyssedre, G.; Laurent, C.
The mechanisms of electroluminescence from large band gap polymers used as insulation in electric components are still under debate. It becomes important to unravel the underlying physics of the emission because of increasing thermo-electric stress and a possible relationship between electroluminescence and field withstand. We report herein on the cathodoluminescence spectra of polyethylene and polypropylene films as a way to uncover the nature of its contributions to electroluminescence emission. It is shown that spectra from the two materials are structured around four elementary components, each of them being associated with a specific process contributing to the overall emission with differentmore » weights depending on excitation conditions and on materials. The cathodoluminescence and electroluminescence spectra of each material are reconstructed from the four spectral components and their relative contribution are discussed. It is shown that electroluminescence from polyethylene and polypropylene has the same origin pointing towards generic mechanisms in both.« less
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Synthesis of cobalt stearate as oxidant additive for oxo-biodegradable polyethylene
NASA Astrophysics Data System (ADS)
Asriza, Ristika O.; Arcana, I. Made
2015-09-01
Cobalt stearate is an oxidant additives that can initiate a process of degradation in high density polyethylene (HDPE). To determine the effect of cobalt stearate in HDPE, oxo-biodegradable polyethylene film was given an irradiation with UV light or heating at various temperature. After given a heating, the FTIR spectra showed a new absorption peak at wave number 1712 cm-1 indicating the presence of carbonyl groups in polymers, whereas after irradiation with UV light is not visible the presence of this absorption peak. The increase concentration of cobalt stearate added in HDPE and the higher heating temperature, the intensity of the absorption peak of the carbonyl group increased. The increasing intensity of the carbonyl group absorption is caused the presence of damage in the film surface after heating, and this result is supported by analysis the surface properties of the film with using SEM. Biodegradation tests were performed on oxo-biodegradable polyethylene film which has been given heating or UV light with using activated sludge under optimal conditions the growth of microorganisms. After biodegradation, the maximum weight decreased by 23% in the oxo-biodegradable polyethylene film with a cobalt stearate concentration of 0.2% and after heating at a temperature of 75 °C for 10 days, and only 0.69% in the same film after irradiation UV light for 10 days. Based on the results above, cobalt stearate additive is more effective to initiate the oxidative degradation of HDPE when it is initiated by heating compared to irradiation with UV light.
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Synthesis of cobalt stearate as oxidant additive for oxo-biodegradable polyethylene
DOE Office of Scientific and Technical Information (OSTI.GOV)
Asriza, Ristika O.; Arcana, I Made, E-mail: arcana@chem.itb.ac.id
Cobalt stearate is an oxidant additives that can initiate a process of degradation in high density polyethylene (HDPE). To determine the effect of cobalt stearate in HDPE, oxo-biodegradable polyethylene film was given an irradiation with UV light or heating at various temperature. After given a heating, the FTIR spectra showed a new absorption peak at wave number 1712 cm{sup −1} indicating the presence of carbonyl groups in polymers, whereas after irradiation with UV light is not visible the presence of this absorption peak. The increase concentration of cobalt stearate added in HDPE and the higher heating temperature, the intensity of themore » absorption peak of the carbonyl group increased. The increasing intensity of the carbonyl group absorption is caused the presence of damage in the film surface after heating, and this result is supported by analysis the surface properties of the film with using SEM. Biodegradation tests were performed on oxo-biodegradable polyethylene film which has been given heating or UV light with using activated sludge under optimal conditions the growth of microorganisms. After biodegradation, the maximum weight decreased by 23% in the oxo-biodegradable polyethylene film with a cobalt stearate concentration of 0.2% and after heating at a temperature of 75 °C for 10 days, and only 0.69% in the same film after irradiation UV light for 10 days. Based on the results above, cobalt stearate additive is more effective to initiate the oxidative degradation of HDPE when it is initiated by heating compared to irradiation with UV light.« less
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Profiles in garbage: Polyethylene terephthalate
DOE Office of Scientific and Technical Information (OSTI.GOV)
Miller, C.
1997-11-01
Polyethylene terephthalate (PET) is a plastic resin used primarily to make bottles. Soft drinks -- along with salad dressing, fruit juices, peanut butter, and other household and consumer products -- use PET bottles. PET also is used for film, sheeting for cups and food trays, oven-safe trays, and other uses. PET is a relatively new packaging resin, first commercialized in the early 1970s. Because it is an ``engineered`` resin, PET is more expensive than commodity resins such as high-density polyethylene (HDPE) and, for the same reason, it is usually the highest valued plastic recyclable.
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NASA Astrophysics Data System (ADS)
Pat, Suat; Özen, Soner; Korkmaz, Şadan
2018-01-01
We report the influence of Sn doping on microstructure, surface, and optical properties of GaN thin films deposited on glass and polyethylene terephthalate (PET) substrate. Sn-doped GaN thin films have been deposited by thermionic vacuum arc (TVA) at low temperature. TVA is a rapid deposition technology for thin film growth. Surface and optical properties of the thin films were presented. Grain size, height distribution, roughness values were determined. Grain sizes were calculated as 20 nm and 13 nm for glass and PET substrates, respectively. Nano crystalline forms were shown by field emission scanning electron microscopy. Optical band gap values were determined by optical methods and photoluminescence measurement. The optical band gap values of Sn doped GaN on glass and PET were determined to be approximately ˜3.40 eV and ˜3.47 eV, respectively. As a result, TVA is a rapid and low temperature deposition technology for the Sn doped GaN deposited on glass and PET substrate.
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Rahmani, Bahareh; Hosseini, Hedayat; Khani, Mohammadreza; Farhoodi, Mehdi; Honarvar, Zohreh; Feizollahi, Ehsan; Shokri, Babak; Shojaee-Aliabadi, Saeedeh
2017-12-01
This study aimed to develop novel bilayer films based on alginate, chitosan and low-density polyethylene (LDPE) containing different concentrations of summer savory extract (SSE). The cold atmospheric plasma system was used to increase the surface energy of LDPE. Initially, water contact angle, surface roughness and the functional group of LDPE before and after plasma treatment were investigated. Then physical, mechanical, optical, antioxidant and microstructure properties of plasma-treated and untreated bilayer films and antioxidant films incorporated with SSE were characterized. Results showed that plasma treatment increased oxygen-containing the polar group, surface roughness and decreased water contact angle of LDPE surface (from 90.47° to 48.73°) and in result enhanced adhesion between polysaccharide coating and LDPE. Tensile strength of both alginate and chitosan coated-LDPE increased from 10.096 to 14.372 and 11.513 to 13.459MPa, respectively after plasma pretreatment. However chitosan-based films had lower water solubility. Although, incorporation of SSE into chitosan and alginate coated-LDPE despite slight adverse effects on the physical and mechanical properties of films, it provided antioxidant activity. Chitosan coated-LDPE containing SSE had potential to use as antioxidant food packaging. Copyright © 2017 Elsevier B.V. All rights reserved.
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NASA Astrophysics Data System (ADS)
Zuo, Biao; Xu, Jianquan; Sun, Shuzheng; Liu, Yue; Yang, Juping; Zhang, Li; Wang, Xinping
2016-06-01
Crystallization is an important property of polymeric materials. In conventional viewpoint, the transformation of disordered chains into crystals is usually a spatially homogeneous process (i.e., it occurs simultaneously throughout the sample), that is, the crystallization rate at each local position within the sample is almost the same. Here, we show that crystallization of ultra-thin poly(ethylene terephthalate) (PET) films can occur in the heterogeneous way, exhibiting a stepwise crystallization process. We found that the layered distribution of glass transition dynamics of thin film modifies the corresponding crystallization behavior, giving rise to the layered distribution of the crystallization kinetics of PET films, with an 11-nm-thick surface layer having faster crystallization rate and the underlying layer showing bulk-like behavior. The layered distribution in crystallization kinetics results in a particular stepwise crystallization behavior during heating the sample, with the two cold-crystallization temperatures separated by up to 20 K. Meanwhile, interfacial interaction is crucial for the occurrence of the heterogeneous crystallization, as the thin film crystallizes simultaneously if the interfacial interaction is relatively strong. We anticipate that this mechanism of stepwise crystallization of thin polymeric films will allow new insight into the chain organization in confined environments and permit independent manipulation of localized properties of nanomaterials.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Zuo, Biao, E-mail: chemizuo@zstu.edu.cn, E-mail: wxinping@yahoo.com; Xu, Jianquan; Sun, Shuzheng
2016-06-21
Crystallization is an important property of polymeric materials. In conventional viewpoint, the transformation of disordered chains into crystals is usually a spatially homogeneous process (i.e., it occurs simultaneously throughout the sample), that is, the crystallization rate at each local position within the sample is almost the same. Here, we show that crystallization of ultra-thin poly(ethylene terephthalate) (PET) films can occur in the heterogeneous way, exhibiting a stepwise crystallization process. We found that the layered distribution of glass transition dynamics of thin film modifies the corresponding crystallization behavior, giving rise to the layered distribution of the crystallization kinetics of PET films,more » with an 11-nm-thick surface layer having faster crystallization rate and the underlying layer showing bulk-like behavior. The layered distribution in crystallization kinetics results in a particular stepwise crystallization behavior during heating the sample, with the two cold-crystallization temperatures separated by up to 20 K. Meanwhile, interfacial interaction is crucial for the occurrence of the heterogeneous crystallization, as the thin film crystallizes simultaneously if the interfacial interaction is relatively strong. We anticipate that this mechanism of stepwise crystallization of thin polymeric films will allow new insight into the chain organization in confined environments and permit independent manipulation of localized properties of nanomaterials.« less
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Biodegradation of poly(hydroxy butanoic acid) copolymer mulch films in soil
NASA Astrophysics Data System (ADS)
Kukade, Pranav
Agricultural mulch films that are used to cover soil of crop rows contribute to earlier maturation of crops and higher yield. Incineration and landfill disposals are the most common means of disposal of the incumbent polyethylene (PE) mulch films; however, these are not environment friendly options. Biodegradable mulch films that can be rototilled into the soil after crop harvest are a promising alternative to offset problems such as landfill disposal, film retrieval and disposal costs. In this study, an in-house laboratory scale test method was developed in which the rate of disintegration, as a result of biodegradation of films based on polyhydroxybutanoic acid (PHB) copolymers was investigated in a soil environment using the residual weight loss method. The influence of soil composition, moisture levels in the soil, and industry-standard anti-microbial additive in the film composition on the rate of disintegration of PHB copolymer films was investigated. The soil composition has significant effect on the disintegration kinetics of PHB copolymer films, since the increasing compost levels in the soil lowered the rate of disintegration of the film. Also, with the increase in moisture level up to a threshold limit, the microbial activity and, hence, the rate of disintegration increased. Lastly, the developed lab-scale test protocol was found to be sensitive to even small concentrations of industry-standard antimicrobial additive in the film composition.
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Xie, Jiazhuo; Wang, Haijun; Wang, Zhou; Zhao, Qinghua; Yang, Yuechao; Waterhouse, Geoffrey I N; Hao, Lei; Xiao, Zihao; Xu, Jing
2018-01-08
Herein, we reported the successful development of novel nanocomposite films based on linear low density polyethylene (LLDPE) with enhanced anti-drop, optical, mechanical, thermal and water vapor barrier properties by introducing organophilic layered double hydroxides (OLDHs) nanosheets. OLDHs loadings were varied from 0-6 wt.%. Structural analyses using the Fourier transform infrared spectrum (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) indicated that the OLDHs nanosheets were homogeneously dispersed with an ordered alignment in the LLDPE matrix. The LLDPE film containing 2 wt.% OLDHs (denoted as OLDHs-2) showed the optimal mechanical, thermal and water vapor barrier properties, whilst the anti-drop and optical performance of the films improved with increasing OLDHs content. The enhanced antidrop properties of the composite films relative to pristine LLDPE can be expected to effectively reduce agricultural losses to disease when the films are applied as agricultural films, whilst the superior light transmittance and water-retaining properties of the composite films will boost agricultural production. Results presented suggest that multifunctional LLDPE/OLDHs nanocomposites show great promise as low cost agricultural plastic films.
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NASA Astrophysics Data System (ADS)
Kamata, Noritsugu; Yuji, Toshifumi; Thungsuk, Nuttee; Arunrungrusmi, Somchai; Chansri, Pakpoom; Kinoshita, Hiroyuki; Mungkung, Narong
2018-06-01
The surface chemical structure of poly(ethylene naphthalate) (PEN) films treated with a low-pressure, high-frequency plasma was investigated by storing in a box at room temperature to protect the PEN film surface from dust. The functional groups on the PEN film surface changed over time. The functional groups of –C=O, –COH, and –COOH were abundant in the Ar + O2 mixture gas plasma-treated PEN samples as compared with those in untreated PEN samples. The changes occurred rapidly after 2 d following the plasma treatment, reaching steady states 8 d after the treatment. Hydrophobicity had an inverse relationship with the concentration of these functional groups on the surface. Thus, the effect of the low-pressure high-frequency plasma treatment on PEN varies as a function of storage time. This means that radical oxygen and oxygen molecules are clearly generated in the plasma, and this is one index to confirm that radical reaction has definitely occurred between the gas and the PEN film surface with a low-pressure high-frequency plasma.
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Zhao, Jun; Chen, Min; Wang, Xiaoyan; Zhao, Xiaodong; Wang, Zhenwen; Dang, Zhi-Min; Ma, Lan; Hu, Guo-Hua; Chen, Fenghua
2013-06-26
In this paper, the triple shape memory effects (SMEs) observed in chemically cross-linked polyethylene (PE)/polypropylene (PP) blends with cocontinuous architecture are systematically investigated. The cocontinuous window of typical immiscible PE/PP blends is the volume fraction of PE (v(PE)) of ca. 30-70 vol %. This architecture can be stabilized by chemical cross-linking. Different initiators, 2,5-dimethyl-2,5-di(tert-butylperoxy)-hexane (DHBP), dicumylperoxide (DCP) coupled with divinylbenzene (DVB) (DCP-DVB), and their mixture (DHBP/DCP-DVB), are used for the cross-linking. According to the differential scanning calorimetry (DSC) measurements and gel fraction calculations, DHBP produces the best cross-linking and DCP-DVB the worst, and the mixture, DHBP/DCP-DVB, is in between. The chemical cross-linking causes lower melting temperature (Tm) and smaller melting enthalpy (ΔHm). The prepared triple shape memory polymers (SMPs) by cocontinuous immiscible PE/PP blends with v(PE) of 50 vol % show pronounced triple SMEs in the dynamic mechanical thermal analysis (DMTA) and visual observation. This new strategy of chemically cross-linked immiscible blends with cocontinuous architecture can be used to design and prepare new SMPs with triple SMEs.
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Jurkiewicz, Elke; Husemann, Ute; Greller, Gerhard; Barbaroux, Magali; Fenge, Christel
2014-01-01
Single-use bioprocessing bags and bioreactors gained significant importance in the industry as they offer a number of advantages over traditional stainless steel solutions. However, there is continued concern that the plastic materials might release potentially toxic substances negatively impacting cell growth and product titers, or even compromise drug safety when using single-use bags for intermediate or drug substance storage. In this study, we have focused on the in vitro detection of potentially cytotoxic leachables originating from the recently developed new polyethylene (PE) multilayer film called S80. This new film was developed to guarantee biocompatibility for multiple bioprocess applications, for example, storage of process fluids, mixing, and cell culture bioreactors. For this purpose, we examined a protein-free cell culture medium that had been used to extract leachables from freshly gamma-irradiated sample bags in a standardized cell culture assay. We investigated sample bags from films generated to establish the operating ranges of the film extrusion process. Further, we studied sample bags of different age after gamma-irradiation and finally, we performed extended media extraction trials at cold room conditions using sample bags. In contrast to a nonoptimized film formulation, our data demonstrate no cytotoxic effect of the S80 polymer film formulation under any of the investigated conditions. The S80 film formulation is based on an optimized PE polymer composition and additive package. Full traceability alongside specifications and controls of all critical raw materials, and process controls of the manufacturing process, that is, film extrusion and gamma-irradiation, have been established to ensure lot-to-lot consistency. © 2014 American Institute of Chemical Engineers.
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Jing, Ziang; Li, Changming; Zhao, Hong; Zhang, Guiling; Han, Baozhong
2016-01-01
The doping effect of graphene nanoplatelets (GNPs) on electrical insulation properties of polyethylene (PE) was studied by combining experimental and theoretical methods. The electric conduction properties and trap characteristics were tested for pure PE and PE/GNPs composites by using a direct measurement method and a thermal stimulated current (TSC) method. It was found that doping smaller GNPs is more beneficial to decrease the conductivity of PE/GNPs. The PE/GNPs composite with smaller size GNPs mainly introduces deep energy traps, while with increasing GNPs size, besides deep energy traps, shallow energy traps are also introduced. These results were also confirmed by density functional theory (DFT) and the non-equilibrium Green’s function (NEGF) method calculations. Therefore, doping small size GNPs is favorable for trapping charge carriers and enhancing insulation ability, which is suggested as an effective strategy in exploring powerful insulation materials. PMID:28773802
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Elastomer modified polypropylene–polyethylene blends as matrices for wood flour–plastic composites
Craig Clemons
2010-01-01
Blends of polyethylene (PE) and polypropylene (PP) could potentially be used as matrices for woodâplastic composites (WPCs). The mechanical performance and morphology of both the unfilled blends and wood-filled composites with various elastomers and coupling agents were investigated. Blending of the plastics resulted in either small domains of the minor phase in a...
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Zhao, Feng; Wang, Chuan; Fan, Yubo
2015-01-01
Wear of polyethylene (PE) tibial inserts is a significant cause of implant failure of total knee arthroplasty (TKA). PE inserts wear measurement and evaluation is the key in TKA researches. There are many methods to measure insert wear. Qualitative methods such as observation are used to determine the wear and its type. Quantitative methods such as gravimetric analysis, coordinate measuring machines (CMM) and micro-computed tomography (micro-CT) are used to measure the mass, volume and geometry of wear. In this paper, the principle, characteristics and research progress of main insert wear evaluation method were introduced and the problems and disadvantages were analyzed.
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Polyethylene bio-degradation by caterpillars of the wax moth Galleria mellonella.
Bombelli, Paolo; Howe, Christopher J; Bertocchini, Federica
2017-04-24
Plastics are synthetic polymers derived from fossil oil and largely resistant to biodegradation. Polyethylene (PE) and polypropylene (PP) represent ∼92% of total plastic production. PE is largely utilized in packaging, representing ∼40% of total demand for plastic products (www.plasticseurope.org) with over a trillion plastic bags used every year [1]. Plastic production has increased exponentially in the past 50 years (Figure S1A in Supplemental Information, published with this article online). In the 27 EU countries plus Norway and Switzerland up to 38% of plastic is discarded in landfills, with the rest utilized for recycling (26%) and energy recovery (36%) via combustion (www.plasticseurope.org), carrying a heavy environmental impact. Therefore, new solutions for plastic degradation are urgently needed. We report the fast bio-degradation of PE by larvae of the wax moth Galleria mellonella, producing ethylene glycol. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Warenda, Monika; Richter, Anne; Schmidt, Diana; Janke, Andreas; Müller, Martin; Simon, Frank; Zimmermann, Ralf; Eichhorn, Klaus-Jochen; Voit, Brigitte; Appelhans, Dietmar
2012-09-14
For using successful (ultra)thin dendritic macromolecule films in (bio)sensing and microfluidic devices and for obtaining reproducible film properties, alteration effects arising from precoatings have to be avoided. Here, oligosaccharide-modified hyperbranched poly(ethylene imine)s (PEI-OS) were used to fabricate very thin PEI-OS films (15-20 nm in dry state), cross-linked with citric acid under condensation, and vacuum condition. However, no reactive precoating is necessary to obtain stable films, which allows very simple film preparation and avoids alteration of the PEIS-OS film properties arising from precoating. Several methods [(in situ) ellipsometry, AFM, XPS, (in situ) ATR-IR, streaming potential measurements] were applied to characterize homogeneity, surface morphology, and stability of these PEI-OS films between pH 2 and pH 10, but also the low protein adsorption behavior. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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EFFECTS OF TRITIUM EXPOSURE ON UHMW-PE, PTFE, AND VESPEL
DOE Office of Scientific and Technical Information (OSTI.GOV)
Clark, E; Kirk Shanahan, K
2006-05-31
Samples of three polymers, Ultra-High Molecular Weight Polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, also known as Teflon{reg_sign}), and Vespel{reg_sign} polyimide were exposed to 1 atmosphere of tritium gas at ambient temperature for varying times up to 2.3 years in closed containers. Sample mass and size measurements (to calculate density), spectra-colorimetry, dynamic mechanical analysis (DMA), and Fourier-transform infrared spectroscopy (FT-IR) were employed to characterize the effects of tritium exposure on these samples. Changes of the tritium exposure gas itself were characterized at the end of exposure by measuring total pressure and by mass spectroscopic analysis of the gas composition. None of the polymersmore » exhibited significant changes of density. The color of initially white UHMW-PE and PTFE dramatically darkened to the eye and the color also significantly changed as measured by colorimetry. The bulk of UHMW-PE darkened just like the external surfaces, however the fracture surface of PTFE appeared white compared to the PTFE external surfaces. The white interior could have been formed while the sample was breaking or could reflect the extra tritium dose at the surface directly from the gas. The dynamic mechanical response of UHMW-PE was typical of radiation effects on polymers- an initial stiffening (increased storage modulus) and reduction of viscous behavior after three months exposure, followed by lowering of the storage modulus after one year exposure and longer. The storage modulus of PTFE increased through about nine months tritium exposure, then the samples became too weak to handle or test using DMA. Characterization of Vespel{reg_sign} using DMA was problematic--sample-to-sample variations were significant and no systematic change with tritium exposure could be discerned. Isotopic exchange and incorporation of tritium into UHMW-PE (exchanging for protium) and into PTFE (exchanging for fluorine) was observed by FT-IR using an
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NASA Astrophysics Data System (ADS)
Heya, Akira; Matsuo, Naoto
2007-07-01
The surface modification of a plastic substrate by atomic hydrogen annealing (AHA) was investigated for flexible displays. In this method, the plastic substrate was exposed to atomic hydrogen generated by cracking hydrogen molecules on heated tungsten wire. Both surface roughness and contact angle of water droplet on poly(ethylene naphthalate) (PEN) substrates were increased by AHA. The surface of a PEN substrate was reduced by atomic hydrogen without optical transmittance degradation. In addition, the properties of a silicon nitride (SiNx) film deposited on a PEN substrate were changed by AHA, and the adhesion between the SiNx film and the PEN substrate was excellent for application to flexible displays.
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Melt Miscibility in Block Copolymers Containing Polyethylene and Substituted Polynorbornenes
NASA Astrophysics Data System (ADS)
Mulhearn, William; Register, Richard
Very few polymer species exist with a sufficiently weak repulsive interaction against polyethylene (PE), characterized by a low Flory parameter χ or interaction energy density X, to be useful for preparing PE-containing block copolymers with disordered melts at high molecular weights. Most suitably miscible polymers are chemically similar to PE, such as copolymers of ethylene with a minority content of an α-olefin, and so are only marginally useful for property modification due to similar physical properties like the glass transition temperature (Tg) . However, the family of polymers consisting of substituted norbornenes prepared via ring-opening metathesis polymerization (ROMP) and subsequent hydrogenation is unique in that many of its members exhibit very low X against PE (comparable with the interaction energy between poly(ethylene-alt-propylene) and PE), and some of these also exhibit high Tg. The miscibility between PE and a substituted, hydrogenated ROMP polynobornene, or between two dissimilar hydrogenated polynorbornenes, is a strong function of the substituent appended to the norbornene monomer. The mixing thermodynamics of this polymer series are irregular, in that the interaction energies do not follow X = (δ1 - δ2)2 where δ is the solubility parameter. However, other systematic trends do apply and we develop a set of mixing rules to quantitatively describe the experimental miscibility behavior. We also investigate statistical copolymerization of two norbornene monomers as a means to continuously tune miscibility with a homopolymer of a third monomer.
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Cross-linked compared with historical polyethylene in THA: an 8-year clinical study.
Geerdink, Carel H; Grimm, Bernd; Vencken, Wendy; Heyligers, Ide C; Tonino, Alphons J
2009-04-01
Wear particle-induced osteolysis is a major cause of aseptic loosening in THA. Increasing wear resistance of polyethylene (PE) occurs by increasing the cross-link density and early reports document low wear rates with such implants. To confirm longer-term reductions in wear we compared cross-linked polyethylene (irradiation in nitrogen, annealing) with historical polyethylene (irradiation in air) in a prospective, randomized clinical study involving 48 patients who underwent THAs with a minimum followup of 7 years (mean, 8 years; range, 7-9 years). The insert material was the only variable. The Harris hip score, radiographic signs of osteolysis, and polyethylene wear were recorded annually. Twenty-three historical and 17 moderately cross-linked polyethylene inserts were analyzed (five patients died, three were lost to followup). At 8 years, the wear rate was lower for cross-linked polyethylene (0.088 +/- 0.03 mm/year) than for the historical polyethylene (0.142 +/- 0.07 mm/year). This reduction (38%) did not diminish with time (33% at 5 years). Acetabular cyst formation was less frequent (39% versus 12%), affected fewer DeLee and Charnley zones (17% versus 4%), and was less severe for the cross-linked polyethylene. The only revision was for an aseptically loose cup in the historical polyethylene group. Moderately cross-linked polyethylene maintained its wear advantage with time and produced less osteolysis, showing no signs of aging at mid-term followup. Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
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Rheological and mechanical properties of recycled polyethylene films contaminated by biopolymer.
Gere, D; Czigany, T
2018-06-01
Nowadays, with the increasing amount of biopolymers used, it can be expected that biodegradable polymers (e.g. PLA, PBAT) may appear in the petrol-based polymer waste stream. However, their impact on the recycling processes is not known yet; moreover, the properties of the products made from contaminated polymer blends are not easily predictable. Therefore, our goal was to investigate the rheological and mechanical properties of synthetic and biopolymer compounds. We made different compounds from regranulates of mixed polyethylene film waste and original polylactic acid (PLA) by extruison, and injection molded specimens from the compounds. We investigated the rheological properties of the regranulates, and the mechanical properties of the samples. When PLA was added, the viscosity and specific volume of all the blends decreased, and mechanical properties (tensile strength, modulus, and impact strength) changed significantly. Young's modulus increased, while elongation at break and impact strength decreased with the increase of the weight fraction of PLA. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Rtimi, Sami; Pulgarin, Cesar; Nadtochenko, Victor A.; Gostev, Fedor E.; Shelaev, Ivan V.; Kiwi, John
2016-01-01
This study presents the first report addressing the effect of FeOx-TiO2 films microstructure on the transients detected by fast spectroscopy related to the long-range bacterial inactivation performance. The different fast kinetic femtosecond transient spectroscopy is reported for each FeOx+TiO2 microstructure. The lifetime of the short transient-species and the oxidative intermediate radicals generated under light were identified. Co-sputtered FeOx-TiO2 on polyethylene films presenting random distribution for both oxides were compared with sequentially sputtered FeOx/TiO2 films made up only by FeOx in the topmost layers. The ratio FeOx:TiO2 was optimized to attain the highest photo-conversion. By X-ray fluorescence, the Fe:Ti ration was found to be ~1.4 in the film bulk and by XPS-etching a ratio of 4:1 was found on the photocatalyst top-most layers. For co-sputtered FeOx-TiO2-PE films, the FeOx-TiO2 heterojunction led to electron injection from the FeOx to lower-lying TiO2 trapping states. The film optical properties, particle size, roughness, hydrophobic-hydrophilic shift and temporal evolution of the transient redox states were characterized in detail. Films with different microstructure led to different antibacterial activity. This suggests that the FeOx-TiO2-PE microstructure and not the position of the potential energy level of the semiconductors FeOx and TiO2 control the charge transfer under light irradiation. PMID:27443505
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Rtimi, Sami; Pulgarin, Cesar; Nadtochenko, Victor A; Gostev, Fedor E; Shelaev, Ivan V; Kiwi, John
2016-07-22
This study presents the first report addressing the effect of FeOx-TiO2 films microstructure on the transients detected by fast spectroscopy related to the long-range bacterial inactivation performance. The different fast kinetic femtosecond transient spectroscopy is reported for each FeOx+TiO2 microstructure. The lifetime of the short transient-species and the oxidative intermediate radicals generated under light were identified. Co-sputtered FeOx-TiO2 on polyethylene films presenting random distribution for both oxides were compared with sequentially sputtered FeOx/TiO2 films made up only by FeOx in the topmost layers. The ratio FeOx:TiO2 was optimized to attain the highest photo-conversion. By X-ray fluorescence, the Fe:Ti ration was found to be ~1.4 in the film bulk and by XPS-etching a ratio of 4:1 was found on the photocatalyst top-most layers. For co-sputtered FeOx-TiO2-PE films, the FeOx-TiO2 heterojunction led to electron injection from the FeOx to lower-lying TiO2 trapping states. The film optical properties, particle size, roughness, hydrophobic-hydrophilic shift and temporal evolution of the transient redox states were characterized in detail. Films with different microstructure led to different antibacterial activity. This suggests that the FeOx-TiO2-PE microstructure and not the position of the potential energy level of the semiconductors FeOx and TiO2 control the charge transfer under light irradiation.
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NASA Astrophysics Data System (ADS)
Rtimi, Sami; Pulgarin, Cesar; Nadtochenko, Victor A.; Gostev, Fedor E.; Shelaev, Ivan V.; Kiwi, John
2016-07-01
This study presents the first report addressing the effect of FeOx-TiO2 films microstructure on the transients detected by fast spectroscopy related to the long-range bacterial inactivation performance. The different fast kinetic femtosecond transient spectroscopy is reported for each FeOx+TiO2 microstructure. The lifetime of the short transient-species and the oxidative intermediate radicals generated under light were identified. Co-sputtered FeOx-TiO2 on polyethylene films presenting random distribution for both oxides were compared with sequentially sputtered FeOx/TiO2 films made up only by FeOx in the topmost layers. The ratio FeOx:TiO2 was optimized to attain the highest photo-conversion. By X-ray fluorescence, the Fe:Ti ration was found to be ~1.4 in the film bulk and by XPS-etching a ratio of 4:1 was found on the photocatalyst top-most layers. For co-sputtered FeOx-TiO2-PE films, the FeOx-TiO2 heterojunction led to electron injection from the FeOx to lower-lying TiO2 trapping states. The film optical properties, particle size, roughness, hydrophobic-hydrophilic shift and temporal evolution of the transient redox states were characterized in detail. Films with different microstructure led to different antibacterial activity. This suggests that the FeOx-TiO2-PE microstructure and not the position of the potential energy level of the semiconductors FeOx and TiO2 control the charge transfer under light irradiation.
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Low polarity water, a novel transition species at the polyethylene-water interface.
Kosower, Edward M; Borz, Galina
2015-10-14
The bridge between water repelling and water-attracting regions is recognized here as low polarity water, a novel "neutral" form of water; its identity as a dipole-dipole water dimer is supported by spectroscopic evidence of its presence in thin films of water on a polyethylene surface. High resolution (0.5 cm(-1)), low signal energies (Sg 100) and short scans (0.1 s) are used to ensure that all peaks are detected. Thin films may be trapped between two polyethylene windows, affirming the low polarity of such water; the spectra of the trapped films ("sandwich") are similar to those from a subtraction procedure. Use of the "sandwich" is a new and useful technique in surface studies. In general, intermediate forms might bridge incompatibility between different regimes, from sets of molecules (chemistry and physics) to sets of organisms (biology and sociology). Thin films of water on polyethylene also display strong and transient peaks of water oligomers, cyclic pentamers and cyclic hexamers (chair and boat), bicyclic hexamers (books 1 and 2) and tricyclic hexamers (prism) that have been previously identified in thin films of water on a silver halide surface.
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USDA-ARS?s Scientific Manuscript database
Washed ‘Marsh’ white grapefruit were placed in polyethylene (PE) bags (1 mil) with or without micro-perforation holes (representing 0.002% of the bag surface) and evaluated for juice quality, firmness, and the development of decay and disorders during storage for 30, 60, or 90 days at 50oF. Each tre...
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Crowley, Michael M; Fredersdorf, Anke; Schroeder, Britta; Kucera, Shawn; Prodduturi, Suneela; Repka, Michael A; McGinity, James W
2004-08-01
Films containing polyethylene oxide (PEO) and a model drug, either guaifenesin (GFN) or ketoprofen (KTP), were prepared by hot-melt extrusion. The thermal properties of the hot-melt extruded films were investigated using differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) was used to examine the surface morphology of the films, and wide angle X-ray diffraction (XRD) was used to investigate the crystalline properties of the polymer, drugs and physical mixtures as well as the solid state structure of the films. The stability of the polymer was studied using gel permeation chromatography. The mechanical properties, including percent elongation and tensile strength of the films, were determined on an Instron according to American Society for Testing Materials (ASTM) procedures. The Hansen solubility parameter was calculated using the Hoftyzer or van Krevelen method to estimate the likelihood of drug--polymer miscibility. Both GFN and KTP were stable during the extrusion process. Melting points corresponding to the crystalline drugs were not observed in the films. Crystallization of GFN on the surface of the film was observed at all concentrations studied, however KTP crystallization did not occur until reaching the 15% level. Guaifenesin and ketoprofen were found to decrease drive load, increase PEO stability and plasticize the polymer during extrusion. The Hansen solubility parameters predicted miscibility between PEO and KTP and poor miscibility between PEO and GFN. The predictions of the solubility parameters were in agreement with the XRD and SEM results. The percent elongation decreased with increasing GFN concentrations and significantly increased with increasing levels of KTP. Both GFN and KTP decreased the tensile strength of the extruded film.
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Becaro, Aline A; Puti, Fernanda C; Correa, Daniel S; Paris, Elaine C; Marconcini, José M; Ferreira, Marcos D
2015-03-01
This paper reports the antibacterial effect and physico-chemical characterization of films containing silver nanoparticles for use as food packaging. Two masterbatches (named PEN and PEC) con- taining silver nanoparticles embedded in distinct carriers (silica and titanium dioxide) were mixed with low-density polyethylene (LDPE) in different compositions and extruded to produce plain films. These films were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC), Thermogravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR). The morphology of the films showed the formation of agglomerates of nanoparticles in both PEN and PEC composites. X-ray analyses confirmed the presence of SiO2 in PEN samples and TiO2 in PEC samples. Thermal analyses indicated an increase in thermal stability of the PEC compositions. The antimicrobial efficacy was determined by applying the test strain for Escherichia coli and Staphylococcus aureus, according to the Japanese Industrial Standard Method (JIS Z 2801:2000). The films analyzed showed antimicrobial properties against the tested microorganisms, presenting better activity against the S. aureus than E. Coli. These findings suggest that LDPE films with silver nanoparticles are promising to provide a significant contribution to the quality and safety of packaged food.
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USDA-ARS?s Scientific Manuscript database
Low density polyethylene (LDPE) was prepared into micro- or submicro-spheres or nanofibers via melt blending or extrusion of cellulose acetate butyrate (CAB)/LDPE immiscible blends and subsequent removal of the CAB matrix. The sizes of the PE spheres or fibers can be successfully controlled by varyi...
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Cyndari, Karen I; Goodheart, Jacklyn R; Miller, Mark A; Oest, Megan E; Damron, Timothy A; Mann, Kenneth A
2017-07-01
Loss of mechanical interlock between cement and bone with in vivo service has been recently quantified for functioning, nonrevised, cemented total knee arthroplasties (TKAs). The cause of interlocking trabecular resorption is not known. The goal of this study is to quantify the distribution of PE debris at the cement-bone interface and determine if polyethylene (PE) debris is locally associated with loss of interlock. Fresh, nonrevised, postmortem-retrieved TKAs (n = 8) were obtained en bloc. Laboratory-prepared constructs (n = 2) served as negative controls. The intact cement-bone interface of each proximal tibia was embedded in Spurr's resin, sectioned, and imaged under polarized light to identify birefringent PE particles. PE wear particle number density was quantified at the cement-bone interface and distal to the interface, and then compared with local loss of cement-bone interlock. The average PE particle number density for postmortem-retrieved TKAs ranged from 8.6 (1.3) to 24.9 (3.1) particles/mm 2 (standard error) but was weakly correlated with years in service. The average particle number density was twice as high as distal (>5mm) to the interface compared to at the interface. The local loss of interlock at the interface was not related to the presence, absence, or particle density of PE. PE debris can migrate extensively along the cement-bone interface of well-fixed tibial components. However, the amount of local bone loss at the cement-bone interface was not correlated with the amount of PE debris at the interface, suggesting that the observed loss of trabecular interlock in these well-fixed TKAs may be due to alternative factors. Copyright © 2017 Elsevier Inc. All rights reserved.
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Laser-induced crystallization of calcium phosphate coatings on polyethylene (PE).
Feddes, Bastiaan; Vredenberg, Arjen M; Wehner, Martin; Wolke, Joop C G; Jansen, John A
2005-05-01
Calcium phosphate (CaP) coatings are used for obtaining a desired biological response. Usually, CaP coatings on metallic substrates are crystallized by annealing at temperatures of at least 400-600 degrees C. For polymeric substrates, this annealing is not possible due to the low melting temperatures. In this work, we present a more suitable method for obtaining crystalline coatings on polymeric substrates, namely laser crystallization. We were successful in obtaining hydroxyapatite coatings on polyethylene. Because of the UV transmission characteristics of the CaP coatings, the use of a low wavelength (157 nm) F(2) laser was necessary for this. As a result of the laser treatment, the CaP coating broke up into islands. The cracks between the islands became larger and the surface became porous with increasing laser energy. The mechanism behind the formation of this morphology did not become clear. However, the fact that crystalline CaP coatings can be obtained on polymeric substrates in an easy way, possibly allows for the development of new products.
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NASA Astrophysics Data System (ADS)
Hu, Wen-Juan; Xie, Fen-Yan; Chen, Qiang; Weng, Jing
2008-10-01
We present polyethylene oxide (PEO) functional films polymerized by rf plasma-enhanced vapour chemical deposition (rf-PECVD) on p-Si (100) surface with precursor ethylene glycol dimethyl ether (EGDME) and diluted Ar in pulsed plasma mode. The influences of discharge parameters on the film properties and compounds are investigated. The film structure is analysed by Fourier transform infrared (FTIR) spectroscopy. The water contact angle measurement and atomic force microscope (AFM) are employed to examine the surface polarity and to detect surface morphology, respectively. It is concluded that the smaller duty cycle in pulsed plasma mode contributes to the rich C-O-C (EO) group on the surfaces. As an application, the adsorption behaviour of platelet-rich plasma on plasma polymerization films performed in-vitro is explored. The shapes of attached cells are studied in detail by an optic invert microscope, which clarifies that high-density C-O-C groups on surfaces are responsible for non-fouling adsorption behaviour of the PEO films.
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NASA Astrophysics Data System (ADS)
Leung, S. Y. Y.; Nikezic, D.; Leung, J. K. C.; Yu, K. N.
2007-10-01
Solid-state nuclear track detectors (SSNTDs) in diffusion chambers have been routinely used for long-term measurements of radon gas concentrations. In usual practice, a filter is added across the top of the diffusion chamber to stop the progeny from entering. Thoron can also be deterred from entering the diffusion chamber by using a polyethylene (PE) membrane. However, the thickness of the PE membrane is rarely specified in the literature. In this paper, we will present our experimental results for a radon exposure that the number of alpha-particle tracks registered by the LR 115 SSNTD in a Karlsruhe diffusion chamber covered with one layer of PE membrane is actually enhanced. This is explained by enhanced deposition of radon progeny on the outside surface of the PE membrane and the insufficient thickness of the PE membrane to stop the alpha particles emitted from these deposited radon progeny to reach the SSNTD. We will present the PE thickness which can stop the alpha particles emitted from the deposited radon or thoron progeny. For the "twin diffusion chambers method", one of the diffusion chambers is covered with PE membranes. The optimal number of thickness of PE membranes will be determined, which allows the largest amount of radon gas to diffuse into the diffusion chamber while at the same time screening out the largest amount of thoron gas.
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Tan, Wensheng; Wang, Xiao
2017-01-01
Due to their large compatibility difference, polyethylene (PE) and polyoxymethylene (POM) cannot be welded together by laser transmission welding. In this study, PE and POM are pretreated using plasma that significantly enhances their laser transmission welding strength. To understand the mechanism underlying the laser welding strength enhancement, surface modification is analyzed using contact angle measurements, atomic force microscopy (AFM), optical microscopy, and X-ray photoelectron spectroscopy (XPS). Characterization results show that the plasma surface treatment improves the surface free energy, significantly enhancing the wettability of the materials. The increase in surface roughness and the generation of homogeneous bubbles contribute to the formation of mechanical micro-interlocking. The oxygen-containing groups introduced by the oxygen plasma treatment improve the compatibility of PE and POM, and facilitate the diffusion and entanglement of molecular chains and the formation of van der Waals force. PMID:29278367
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Liu, Huixia; Jiang, Yingjie; Tan, Wensheng; Wang, Xiao
2017-12-26
Due to their large compatibility difference, polyethylene (PE) and polyoxymethylene (POM) cannot be welded together by laser transmission welding. In this study, PE and POM are pretreated using plasma that significantly enhances their laser transmission welding strength. To understand the mechanism underlying the laser welding strength enhancement, surface modification is analyzed using contact angle measurements, atomic force microscopy (AFM), optical microscopy, and X-ray photoelectron spectroscopy (XPS). Characterization results show that the plasma surface treatment improves the surface free energy, significantly enhancing the wettability of the materials. The increase in surface roughness and the generation of homogeneous bubbles contribute to the formation of mechanical micro-interlocking. The oxygen-containing groups introduced by the oxygen plasma treatment improve the compatibility of PE and POM, and facilitate the diffusion and entanglement of molecular chains and the formation of van der Waals force.
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Krenn, V; Hopf, F; Thomas, P; Thomsen, M; Usbeck, S; Boettner, F; Müller, S; Saberi, D; Hügle, T; Huber, M; Scheuber, L; Hopf, J C; Kretzer, J P
2016-03-01
The identification of particles of prosthesis material components in the histopathological diagnosis of synovialitis is of great importance in the evaluation of implant failure. In histopathological particle algorithms, polyethylene (PE) particles with a maximum length of less than 100 µm are designated with the term macroparticles; however, a systematic investigation and characterization are lacking. In SLIM knee specimens (n = 24) a minimum value of 210 µm and a maximum value of 2100 µm were measured; the mathematical mean length varied between 235 µm and 1416 µm. In SLIM hip specimens (n = 11) the minimum value was 290 µm and the maximum value was 1806 µm; the mean length varied between 353 and 1726 µm. Because of this conspicuous size, and to distinguish from PE macroparticles, the designation PE supra-macroparticulate is suggested. This new terminology acknowledges the fact that these PE particles are visible under magnification (e.g., × 12.5) and also macroscopically. The particles were also indirectly proven as there were completely separate and optically clear, column-shaped cavities corresponding to the shape of the PE particles (PE vacuoles). The life of the prosthesis is highly variable at between 12 and 300 months. In all cases loosening of the prosthesis, misalignment of the PE components, and/or damage to the PE inlay occurred. The cause and existence of these supra-macroparticulate PE particles (more than 100 µm) is still unclear. A mechanical malfunction seems probable and should be discussed. In prostheses with short lives the proof of supra-macroparticulate PE in SLIM could be a sign of an early mechanical problem. In the wider histopathological particle algorithm supra-macroparticulate PE was considered to fall in the category of macroparticles and should be considered in the histopathological diagnosis of implant failure.
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NASA Astrophysics Data System (ADS)
Gomaa, E.; Mostafa, N.; Mohsen, M.; Mohammed, M.
2004-10-01
Positron annihilation lifetime spectroscopy (PALS) was used to study the immiscibility of a polar nitrile rubber (NBR) that had been blended with pure and waste, low- and high-density polyethylene (PE). The effect of the weight percent of the rubber added to the PE was also investigated. It was found that a complicated variation (positive and negative) in both free-volume parameters (τ3 and I 3) from the values of the initial polymers forms an immiscible blend. These results are supported by a significant broadening in the free-volume hole size distributions. This has been interpreted in terms of interfacial spaces created between the boundaries of the two phases. Furthermore, a correlation was established between the free-volume parameters (τ3 and I 3) and the electrical and mechanical properties of the before mentioned polymer blends as a function of the weight percent of waste PE.
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Yoo, Youngmin; Kim, Byung Gon; Pak, Kwanyong; Han, Sung Jae; Song, Heon-Sik; Choi, Jang Wook; Im, Sung Gap
2015-08-26
We report an initiated chemical vapor deposition (iCVD) process to coat polyethylene (PE) separators in Li-ion batteries with a highly cross-linked, mechanically strong polymer, namely, polyhexavinyldisiloxane (pHVDS). The highly cross-linked but ultrathin pHVDS films can only be obtained by a vapor-phase process, because the pHVDS is insoluble in most solvents and thus infeasible with conventional solution-based methods. Moreover, even after the pHVDS coating, the initial porous structure of the separator is well preserved owing to the conformal vapor-phase deposition. The coating thickness is delicately controlled by deposition time to the level that the pore size decreases to below 7% compared to the original dimension. The pHVDS-coated PE shows substantially improved thermal stability and electrolyte wettability. After incubation at 140 °C for 30 min, the pHVDS-coated PE causes only a 12% areal shrinkage (versus 90% of the pristine separator). The superior wettability results in increased electrolyte uptake and ionic conductivity, leading to significantly improved rate performance. The current approach is applicable to a wide range of porous polymeric separators that suffer from thermal shrinkage and poor electrolyte wetting.
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Influence of the stretch wrapping process on the mechanical behavior of a stretch film
NASA Astrophysics Data System (ADS)
Klein, Daniel; Stommel, Markus; Zimmer, Johannes
2018-05-01
Lightweight construction is an ongoing task in packaging development. Consequently, the stability of packages during transport is gaining importance. This study contributes to the optimization of lightweight packaging concepts regarding their stability. A very widespread packaging concept is the distribution of goods on a pallet whereas a Polyethylene (PE) stretch film stabilizes the lightweight structure during the shipment. Usually, a stretch wrapping machine applies this stretch film to the pallet. The objective of this study is to support packaging development with a method that predicts the result of the wrapping process, based on the mechanical characterization of the stretch film. This result is not only defined by the amount of stretch film, its spatial distribution on the pallet and its internal stresses that result in a containment force. More accurate, this contribution also considers the influence of the deformation history of the stretch film during the wrapping process. By focusing on similarities of stretch wrappers rather than on differences, the influence of generalized process parameters on stretch film mechanics and thereby on pallet stability can be determined experimentally. For a practical use, the predictive method is accumulated in an analytic model of the wrapping process that can be verified experimentally. This paves the way for experimental and numerical approaches regarding the optimization of pallet stability.
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NASA Astrophysics Data System (ADS)
Yao, Bingjian; Zhu, Qingzeng; Yao, Linli; Hao, Jingcheng
2015-03-01
A series of poly(ethylene glycol)-block-poly(lactic acid) (PEG-PLA) copolymers with a hydrophobic PLA block of different molecular weights and a fixed length hydrophilic PEG were synthesized successfully and characterized. These amphiphilic block copolymers were used to fabricate honeycomb-structured porous films using the breath figure (BF) templating technique. The surface topology and composition of the highly ordered pattern film were further characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fluorescence microscopy. The results indicated that the PEG-to-PLA block molecular weight ratio influenced the BF film surface topology. The film with the best ordered pores was obtained with a PEG-to-PLA ratio of 2.0 × 103:3.0 × 104. The self-organization of the hydrophilic PEG chains within the pores was confirmed by XPS and fluorescence labeled PEG. A model is proposed to elucidate the stabilization process of the amphiphilic PEG-PLA aggregated architecture on the water droplet-based templates. In addition, GFP-U87 cell viability has been investigated by MTS test and the cell morphology on the honeycomb-structured PEG-PLA porous film has been evaluated using phase-contrast microscope. This porous film is shown to be suitable as a matrix for cell growth.
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NASA Astrophysics Data System (ADS)
Emmanuel, A.; Raghavan, J.
2015-10-01
While LEO and GEO are used for most satellite missions, Highly Elliptical Orbits (HEOs) are also used for satellite missions covering Polar Regions of Earth. Satellites in HEO are exposed to a relatively harsher radiation environment than LEO and GEO. The mass of traditionally used aluminum radiation shield, required to attenuate the radiation to a level below a certain threshold that is safe for the satellite bus and payload, scales with the level of radiation. It has been shown (Emmanuel et al., 2014) that materials with low atomic number (Z) such as polyethylene (PE) can result in a lighter shield than aluminum (Al) in HEO. However, PE has to be reinforced with relatively high Z fibers such as graphite (G) to improve its mechanical properties. The effect of introduction of G and the resulting composite structure (that meets the requirements on mechanical properties, manufacturing and service) on the radiation shielding effectiveness of PE was studied through simulation using a layered PE-G composite. The Total Ionization Dose (TID), deposited in a silicon detector behind the composite shield, has been found to be function of layer volume fraction, layer thickness and stacking sequence of the PE and G layers. One composite configuration has resulted in a TID lower than that for PE, demonstrating the possibility of tailoring the mechanical properties of PE-based composite radiation shield with minimal negative impact on its radiation shielding effectiveness.
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Creating poly(ethylene glycol) film on the surface of NiTi alloy by gamma irradiation
NASA Astrophysics Data System (ADS)
Yu, Hongyan; Yan, Jin; Ma, Huiling; Zeng, Xinmiao; Liu, Yang; Zhao, Xinqing
2015-07-01
NiTi alloy has been extensively utilized as biomaterials owing to its unique shape memory effect, superelasticity and biocompatibility. However, concern with the toxic and allergic responses of nickel potentially releasing from implants stimulated lots of researches of modification on NiTi alloy surface. Creating chemical bond attachment of bioorganic film on NiTi alloy surface could effectively inhibit Ni releasing and obtain bioactive functions for further application. In this work, to get a bioorganic surface, NiTi alloy was modified with poly(ethylene glycol) (PEG) film by gamma ray induced grafting or crosslinking. X-ray diffraction (XRD) spectrum, water contact angle geometer and X-ray photoelectron spectroscopy (XPS) techniques were used to characterize the NiTi surface. The results indicated that PEG was covalent bonded on NiTi alloy surface. Fluorescence microscope (FM) images for morphology of 1 day osteoblast culture on the PEG coated NiTi surface showed that PEG could improve cell proliferation on NiTi surface. Our work offers a way to introduce a bioorganic metal surface by gamma irradiation.
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Brandon, Anja Malawi; Gao, Shu-Hong; Tian, Renmao; Ning, Daliang; Yang, Shan-Shan; Zhou, Jizhong; Wu, Wei-Min; Criddle, Craig S
2018-06-05
Recent studies have demonstrated the ability for polystyrene (PS) degradation within the gut of mealworms ( Tenebrio molitor). To determine whether plastics may be broadly susceptible to biodegradation within mealworms, we evaluated the fate of polyethylene (PE) and mixtures (PE + PS). We find that PE biodegrades at comparable rates to PS. Mass balances indicate conversion of up 49.0 ± 1.4% of the ingested PE into a putative gas fraction (CO 2 ). The molecular weights ( M n ) of egested polymer residues decreased by 40.1 ± 8.5% in PE-fed mealworms and by 12.8 ± 3.1% in PS-fed mealworms. NMR and FTIR analyses revealed chemical modifications consistent with degradation and partial oxidation of the polymer. Mixtures likewise degraded. Our results are consistent with a nonspecific degradation mechanism. Analysis of the gut microbiome by next-generation sequencing revealed two OTUs ( Citrobacter sp. and Kosakonia sp.) strongly associated with both PE and PS as well as OTUs unique to each plastic. Our results suggest that adaptability of the mealworm gut microbiome enables degradation of chemically dissimilar plastics.
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Thomas, John E; Allen, L Hartwell; McCormack, Leslie A; Vu, Joseph C; Dickson, Donald W; Ou, Li-Tse
2004-01-01
The fumigant 1,3-dichloropropene (1,3-D) is considered to be a potential replacement for methyl bromide when methyl bromide is phased out in 2005. This study on surface emissions and subsurface diffusion of 1,3-D in a Florida sandy soil was conducted in field beds with or without plastic covers. After injection of the commercial fumigant Telone II by conventional chisels to field beds at 30cm depth which were covered with polyethylene film (PE), virtually impermeable film, or no cover (bare), (Z)- and (E)-1,3-D rapidly diffused upward. Twenty hours after injection, majority of (Z)- and (E)-1,3-D had moved upward from 30 cm depth to the layer of 5-20 cm depth. Downward movement of the two isomers in the beds with or without a plastic cover was not significant. (Z)-1,3-D diffused more rapidly than (E)-1,3-D. Virtually impermeable films (VIF) had a good capacity to retain (Z)- and (E)-1,3-D in soil pore air space. Vapor concentrations of the two isomers in the shallow subsurface of the field bed covered with VIF were greater than that in the two beds covered with polyethylene film (PE) or no cover (bare). In addition, VIF cover provided more uniform distribution of (Z)- and (E)-1,3-D in shallow subsurface than PE cover or no cover. Virtually impermeable film also had a better capability to retard surface emissions of the two isomers from soil in field beds than PE cover or no cover.
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Lee, Hwang; Byun, Da-Eun; Kim, Ju Min; Kwon, Jung-Hwan
2018-01-01
To evaluate rate of migration from plastic debris, desorption of model hydrophobic organic chemicals (HOCs) from polyethylene (PE)/polypropylene (PP) films to water was measured using PE/PP films homogeneously loaded with the HOCs. The HOCs fractions remaining in the PE/PP films were compared with those predicted using a model characterized by the mass transfer Biot number. The experimental data agreed with the model simulation, indicating that HOCs desorption from plastic particles can generally be described by the model. For hexachlorocyclohexanes with lower plastic-water partition coefficients, desorption was dominated by diffusion in the plastic film, whereas desorption of chlorinated benzenes with higher partition coefficients was determined by diffusion in the aqueous boundary layer. Evaluation of the fraction of HOCs remaining in plastic films with respect to film thickness and desorption time showed that the partition coefficient between plastic and water is the most important parameter influencing the desorption half-life. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Ultra high molecular weight polyethylene: Optical features at millimeter wavelengths
NASA Astrophysics Data System (ADS)
D'Alessandro, G.; Paiella, A.; Coppolecchia, A.; Castellano, M. G.; Colantoni, I.; de Bernardis, P.; Lamagna, L.; Masi, S.
2018-05-01
The next generation of experiments for the measurement of the Cosmic Microwave Background (CMB) requires more and more the use of advanced materials, with specific physical and structural properties. An example is the material used for receiver's cryostat windows and internal lenses. The large throughput of current CMB experiments requires a large diameter (of the order of 0.5 m) of these parts, resulting in heavy structural and optical requirements on the material to be used. Ultra High Molecular Weight (UHMW) polyethylene (PE) features high resistance to traction and good transmissivity in the frequency range of interest. In this paper, we discuss the possibility of using UHMW PE for windows and lenses in experiments working at millimeter wavelengths, by measuring its optical properties: emissivity, transmission and refraction index. Our measurements show that the material is well suited to this purpose.
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Qi, Jie; Zhang, Huang; Wang, Yingzhou; Mani, Mohan Prasath; Jaganathan, Saravana Kumar
2018-01-01
Currently, the design of extracellular matrix (ECM) with nanoscale properties in bone tissue engineering is challenging. For bone tissue engineering, the ECM must have certain properties such as being nontoxic, highly porous, and should not cause foreign body reactions. In this study, the hybrid scaffold based on polyvinyl alcohol (PVA) blended with metallocene polyethylene (mPE) and plectranthus amboinicus (PA) was fabricated for bone tissue engineering via electrospinning. The fabricated hybrid nanocomposites were characterized by scanning electron microscopy (SEM), Fourier transform and infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), contact angle measurement, and atomic force microscopy (AFM). Furthermore, activated partial thromboplastin time (APTT), prothrombin time (PT), and hemolytic assays were used to investigate the blood compatibility of the prepared hybrid nanocomposites. The prepared hybrid nanocomposites showed reduced fiber diameter (238±45 nm) and also increased porosity (87%) with decreased pore diameter (340±86 nm) compared with pure PVA. The interactions between PVA, mPE, and PA were identified by the formation of the additional peaks as revealed in FTIR. Furthermore, the prepared hybrid nanocomposites showed a decreased contact angle of 51°±1.32° indicating a hydrophilic nature and exhibited lower thermal stability compared to pristine PVA. Moreover, the mechanical results revealed that the electrospun scaffold showed an improved tensile strength of 3.55±0.29 MPa compared with the pristine PVA (1.8±0.52 MPa). The prepared hybrid nanocomposites showed delayed blood clotting as noted in APTT and PT assays indicating better blood compatibility. Moreover, the hemolysis assay revealed that the hybrid nanocomposites exhibited a low hemolytic index of 0.6% compared with pure PVA, which was 1.6% suggesting the safety of the developed nanocomposite to red blood cells (RBCs). The prepared nanocomposites exhibited better physico
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Neti, Venkata S.; Das, Sadananda; Brown, Suree; ...
2017-08-29
Brush-on-brush structures are proposed as one method to overcome support effects in grafted polymers. Utilizing glycidyl methacrylate (GMA) grafted on polyethylene (PE) fibers using radiation-induced graft polymerization (RIGP) provides a hydrophilic surface on the hydrophobic PE. When integrated with atom transfer radical polymerization (ATRP), the grafting of acrylonitrile (AN) and hydroxyethyl acrylate (HEA) can be controlled and manipulated more easily than with RIGP. Poly(acrylonitrile)-co-poly(hydroxyethyl acrylate) chains were grown via ATRP on PE-GMA fibers to generate an adsorbent for the extraction of uranium from seawater. The prepared adsorbents in this study demonstrated promise (159.9 g-U/kg of adsorbent) in laboratory screening testsmore » using a high uranium concentration brine and 1.24 g-U/Kg of adsorbent in the filtered natural seawater in 21-days. Here, the modest capacity in 21-days exceeds previous efforts to generate brush-on-brush adsorbents by ATRP while manipulating the apparent surface hydrophilicity of the trunk material (PE).« less
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Neti, Venkata S.; Das, Sadananda; Brown, Suree
Brush-on-brush structures are proposed as one method to overcome support effects in grafted polymers. Utilizing glycidyl methacrylate (GMA) grafted on polyethylene (PE) fibers using radiation-induced graft polymerization (RIGP) provides a hydrophilic surface on the hydrophobic PE. When integrated with atom transfer radical polymerization (ATRP), the grafting of acrylonitrile (AN) and hydroxyethyl acrylate (HEA) can be controlled and manipulated more easily than with RIGP. Poly(acrylonitrile)-co-poly(hydroxyethyl acrylate) chains were grown via ATRP on PE-GMA fibers to generate an adsorbent for the extraction of uranium from seawater. The prepared adsorbents in this study demonstrated promise (159.9 g-U/kg of adsorbent) in laboratory screening testsmore » using a high uranium concentration brine and 1.24 g-U/Kg of adsorbent in the filtered natural seawater in 21-days. Here, the modest capacity in 21-days exceeds previous efforts to generate brush-on-brush adsorbents by ATRP while manipulating the apparent surface hydrophilicity of the trunk material (PE).« less
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Neti, Venkata S.; Das, Sadananda; Brown, Suree
Brush-on-brush structures are proposed as one method to overcome support effects in grafted polymers. Utilizing glycidyl methacrylate (GMA) grafted on polyethylene (PE) fibers using radiation-induced graft polymerization (RIGP) provides a hydrophilic surface on the hydrophobic PE. When integrated with atom transfer radical polymerization (ATRP), the grafting of acrylonitrile (AN) and hydroxyethyl acrylate (HEA) can be controlled and manipulated more easily than with RIGP. Poly(acrylonitrile)-co-poly(hydroxyethyl acrylate) chains were grown via ATRP on PE-GMA fibers to generate an adsorbent for the extraction of uranium from seawater. The prepared adsorbents in this study demonstrated promise (159.9 g- U/kg of adsorbent) in laboratory screeningmore » tests using a high uranium concentration brine and 1.24 g-U/Kg of adsorbent in the filtered natural seawater in 21-days. The modest capacity in 21- days exceeds previous efforts to generate brush-on-brush adsorbents by ATRP while manipulating the apparent surface hydrophilicity of the trunk material (PE).« less
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NASA Astrophysics Data System (ADS)
Kahraman, S.; Çetinkaya, S.; Yaşar, S.; Bilican, İ.
2014-09-01
In this paper, we report, for the first time, the results of the polyethylene glycol- (PEG) assisted preparation and characterization of high-quality and well-crystallized Cu2SnS3 (CTS) thin films obtained using sol-gel spin-coating method and a subsequent annealing in a sulphur atmosphere. Structural, morphological, compositional, electrical and optical investigations were carried out. The X-ray diffraction patterns of the samples proved the polycrystalline nature and preferred crystallization of the films. No peak referring to other binary or ternary phases were detected in the patterns. The intensity of the preferred orientation and crystallite size of the films increased with increasing PEG content. This trend yielded an improvement in photo-transient currents of the PEG-assisted growth of CTS films. The scanning electron microscopy images revealed that the CTS films have continuous, dense and agglomeration-like morphology. Through energy dispersive X-ray spectroscopy studies, it has been deduced that the samples consist of Cu, Sn and S of which atomic percentages were consistent with Cu/Sn and S/metal initial ratios. The agglomerated morphology of the samples has been attributed to increasing PEG content. A remarkable enhancement was observed in photo-transient currents of p-n junction of the produced films along with increasing PEG content. Through resistivity-temperature measurements, three impurity level electrical activation energy values for each film were found. Optical band gap values of the films were estimated via absorbance-wavelength behaviours and decreased with increasing PEG content. It has been revealed that PEG-assisted growth of CTS thin films is a promising way to improve its photovoltaic characteristics.
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A new method for isolation of polyethylene wear debris from tissue and synovial fluid.
Visentin, Manuela; Stea, Susanna; Squarzoni, Stefano; Antonietti, Barbara; Reggiani, Matteo; Toni, Aldo
2004-11-01
Sub-micron-sized ultrahigh molecular-weight polyethylene (PE) debris is generated in the joint space as a result of articulation and cyclic loading of an orthopaedic implant. Its characterization requires isolation and subsequent analysis by ultra-structural methods. An innovative method based on the digestion of paraffin-embedded tissue samples was proposed. Tissue slices were digested with sodium hypochlorite directly on polycarbonate filter. The same procedure could be applied also to fresh synovial fluid. Plastic particles were not lost or damaged during treatment. Chemical identification of particles was done by micro-Raman spectroscopy that confirmed purity of retrieved PE particles. Size and shape of PE particles were characterised using scanning electron microscopy and were comparable in number and morphology to the retrieval by other authors. Equivalent diameter ranged from 0.48 to 0.95microm and particle number ranged from 9 to 23x10(9)/cm(3).
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NASA Astrophysics Data System (ADS)
Wilson, John Ford
1997-09-01
Ultra high molecular weight polyethylene (UHMW-PE) is used extensively in hip and knee endoprostheses. Radiation damage from the sterilization of these endoprostheses prior to surgical insertion results in polymer crosslinking and decreased oxidative stability. The motivation for this study was to determine if UHMW-PE could be crosslinked by low dose proton irradiation with minimal radiation damage and its subsequent deleterious effects. I found that low dose proton irradiation and post irradiation hydrogen annealing did crosslink UHMW-PE and limit post irradiation oxidation. Crosslinking onset was investigated for UHMW-PE irradiated with 2.6 and 30 MeV H+ ions at low doses from 5.7 × 1011-2.3 × 1014 ions/cm2. Crosslinking was determined from gel permeation chromatography (GPC) of 1,2,4 trichlorobenzene sol fractions and increased with dose. Fourier transform infrared spectroscopy (FTIR) showed irradiation resulted in increased free radicals confirmed from increased carbonyl groups. Radiation damage, especially at the highest doses observed, also showed up in carbon double bonds and increased methyl end groups. Hydrogen annealing after ion irradiation resulted in 40- 50% decrease in FTIR absorption associated with carbonyl. The hydrogen annealing prevented further oxidation after aging for 1024 hours at 80oC. Hydrogen annealing was successful in healing radiation damage through reacting with the free radicals generated during proton irradiation. Polyethylenes, polyesters, and polyamides are used in diverse applications by the medical profession in the treatment of orthopedic impairments and cardiovascular disease and for neural implants. These artificial implants are sterilized with gamma irradiation prior to surgery and the resulting radiation damage can lead to accelerated deterioration of the implant properties. The findings in this study will greatly impact the continued use of these materials through the elimination of many problems associated with radiation
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First-principle simulations of electronic structure in semicrystalline polyethylene
NASA Astrophysics Data System (ADS)
Moyassari, A.; Unge, M.; Hedenqvist, M. S.; Gedde, U. W.; Nilsson, F.
2017-05-01
In order to increase our fundamental knowledge about high-voltage cable insulation materials, realistic polyethylene (PE) structures, generated with a novel molecular modeling strategy, have been analyzed using first principle electronic structure simulations. The PE structures were constructed by first generating atomistic PE configurations with an off-lattice Monte Carlo method and then equilibrating the structures at the desired temperature and pressure using molecular dynamics simulations. Semicrystalline, fully crystalline and fully amorphous PE, in some cases including crosslinks and short-chain branches, were analyzed. The modeled PE had a structure in agreement with established experimental data. Linear-scaling density functional theory (LS-DFT) was used to examine the electronic structure (e.g., spatial distribution of molecular orbitals, bandgaps and mobility edges) on all the materials, whereas conventional DFT was used to validate the LS-DFT results on small systems. When hybrid functionals were used, the simulated bandgaps were close to the experimental values. The localization of valence and conduction band states was demonstrated. The localized states in the conduction band were primarily found in the free volume (result of gauche conformations) present in the amorphous regions. For branched and crosslinked structures, the localized electronic states closest to the valence band edge were positioned at branches and crosslinks, respectively. At 0 K, the activation energy for transport was lower for holes than for electrons. However, at room temperature, the effective activation energy was very low (˜0.1 eV) for both holes and electrons, which indicates that the mobility will be relatively high even below the mobility edges and suggests that charge carriers can be hot carriers above the mobility edges in the presence of a high electrical field.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Ang, P. C.; Ibrahim, K.; Pakhuruddin, M. Z.
2015-04-24
One way to realize low-cost thin film silicon (Si) solar cells fabrication is by depositing the films with high-deposition rate and manufacturing-compatible electron beam (e-beam) evaporation onto inexpensive foreign substrates such as glass or plastic. Most of the ongoing research is reported on e-beam evaporation of Si films on glass substrates to make polycrystalline solar cells but works combining both e-beam evaporation and plastic substrates are still scarce in the literature. This paper studies electrical properties and surface morphology of 1 µm electron beam evaporated Al-doped p-type silicon thin films on textured polyethylene terephthalate (PET) substrate for application as anmore » absorber layer in solar cells. In this work, Si thin films with different doping concentrations (including an undoped reference) are prepared by e-beam evaporation. Energy dispersion X-ray (EDX) showed that the Si films are uniformly doped by Al dopant atoms. With increased Al/Si ratio, doping concentration increased while both resistivity and carrier mobility of the films showed opposite relationships. Root mean square (RMS) surface roughness increased. Overall, the Al-doped Si film with Al/Si ratio of 2% (doping concentration = 1.57×10{sup 16} atoms/cm{sup 3}) has been found to provide the optimum properties of a p-type absorber layer for fabrication of thin film Si solar cells on PET substrate.« less
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Evaluation of fatigue crack behavior in electron beam irradiated polyethylene pipes
NASA Astrophysics Data System (ADS)
Pokharel, Pashupati; Jian, Wei; Choi, Sunwoong
2016-09-01
A cracked round bar (CRB) fatigue test was employed to determine the slow crack growth (SCG) behavior of samples from high density polyethylene (HDPE) pipes using PE4710 resin. The structure property relationships of fatigue failure of polyethylene CRB specimens which have undergone various degree of electron beam (EB) irradiation were investigated by observing fatigue failure strength and the corresponding fracture surface morphology. Tensile test of these HDPE specimens showed improvements in modulus and yield strength while the failure strain decreased with increasing EB irradiation. The CRB fatigue test of HDPE pipe showed remarkable effect of EB irradiation on number of cycles to failure. The slopes of the stress-cycles to failure curve were similar for 0-100 kGy; however, significantly higher slope was observed for 500 kGy EB irradiated pipe. Also, the cycle to fatigue failure was seen to decrease as with EB irradiation in the high stress range, ∆σ=(16 MPa to 10.8 MPa); however, 500 kGy EB irradiated samples showed longer cycles to failure than the un-irradiated specimens at the stress range below 9.9 MPa and the corresponding initial stress intensity factor (∆KI,0)=0.712 MPa m1/2. The fracture surface morphology indicated that the cross-linked network in 500 kGy EB irradiated PE pipe can endure low dynamic load more effectively than the parent pipe.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Rawat, Kusum; Department of Electronic Science, University of Delhi South Campus, Delhi 110021; Kim, Hee-Joon
Highlights: • Cu{sub 2}ZnSnS{sub 4} nanoparticles were synthesized by wet chemical technique. • First report on the effect of using polyethylene glycol as a structure directing agent on Cu{sub 2}ZnSnS{sub 4} nanoparticles. • The morphology of Cu{sub 2}ZnSnS{sub 4} nanoparticles changes into nanoflakes and nanorods structures with polyethylene glycol concentration. • Polyethylene glycol assisted Cu{sub 2}ZnSnS{sub 4} nanoparticle film exhibits optical bandgap of 1.5 eV which is suitable for the application in solar cells. - Abstract: Cu{sub 2}ZnSnS{sub 4} nanoparticles were synthesized by wet chemical technique using metal thiourea precursor at 250 °C. The structural and morphological properties of asmore » grown nanoparticles have been characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. The influence of different concentration of polyethylene glycol as structure directing agent on the morphologies of Cu{sub 2}ZnSnS{sub 4} nanoparticles are investigated on thin films deposited by spin coating technique. The mean crystallite size of the Cu{sub 2}ZnSnS{sub 4} nanoparticles was found to improve with polyethylene glycol concentration. Scanning electron microscopy images of Cu{sub 2}ZnSnS{sub 4} revealed aggregated spherical shaped nanoparticles whereas the polyethylene glycol assisted Cu{sub 2}ZnSnS{sub 4} nanoparticle films show nanoflakes and nanorods structures with increasing concentration of polyethylene glycol. Transmission electron microscopy analysis has also been performed to determine the size and structure of nanorods. UV–vis absorption spectroscopy shows the broad band absorption with optical bandgap of 1.50 eV for polyethylene glycol assisted Cu{sub 2}ZnSnS{sub 4} films.« less
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Hope, Natalie; Bellare, Anuj
2015-03-01
Ultrahigh-molecular-weight polyethylene (UHMWPE) is subjected to radiation crosslinking to form highly crosslinked polyethylene (HXLPE), which has improved wear resistance. First-generation HXLPE was subjected to thermal treatment to reduce or quench free radicals that can induce long-term oxidative degeneration. Most recently, antioxidants have been added to HXLPE to induce oxidative resistance rather than by thermal treatment. However, antioxidants can interfere with the efficiency of radiation crosslinking. We sought to identify (1) which antioxidant from among those tested (vitamin E, β-carotene, butylated hydroxytoluene, or pentaerythritol tetrakis [methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate]) causes the least reduction of crosslinking; (2) which promotes the greatest oxidative stability; and (3) which had the lowest ratio of oxidation index to crosslink density. Medical-grade polyethylene (PE) resin was blended with 0.1 weight % of the following stabilizers: alpha tocopherol (vitamin E), β-carotene, butylated hydroxytoluene (BHT), and pentaerythritol tetrakis [methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (a hindered phenol antioxidant [HPAO]). These blends were compression-molded into sheets and subjected to electron beam irradiation to a dose of 100 kGy. Equilibrium swelling experiments were conducted to calculate crosslink density. Each PE was subjected to accelerated aging for a period of 2 weeks and Fourier transform infrared spectroscopy was used to measure the maximum oxidation. Statistical analysis was conducted using analysis of variance with Fisher's protected least significant difference in which a p value of < 0.05 was used to define a significant difference. The least reduction of crosslinking in antioxidant-containing HXLPE was observed with HPAO, which had a crosslink density (n = 6) of 0.167 (effect size [ES] = 0.87; 95% confidence interval [CI], 0.162-0.173) mol/dm(3) compared with 0.139 (ES = 1.57; 95% CI, 0
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Anderson, Jordan A; Lamichhane, Sujan; Remund, Tyler; Kelly, Patrick; Mani, Gopinath
2016-01-01
Drug-coated balloons (DCBs) are used to treat various cardiovascular diseases. Currently available DCBs carry drug on the balloon surface either solely or using different carriers. Several studies have shown that a significant amount of drug is lost in the blood stream during balloon tracking to deliver only a sub-therapeutic level of drug at the treatment site. This research is focused on developing paclitaxel (PAT) loaded polyethylene oxide (PEO) films (PAT-PEO) as a controlled drug delivery carrier for DCBs. An array of PAT-PEO films were developed in this study to provide tailored release of >90% of drug only at specific time intervals, which is the time frame required for carrying out balloon-based therapy. The characterizations of PAT-PEO films using SEM, FTIR, and DSC showed that the films developed were homogenous and the PAT was molecularly dispersed in the PEO matrix. Mechanical tests showed that most PAT-PEO films developed were flexible and ductile, with yield and tensile strengths not affected after PAT incorporation. The viability, proliferation, morphology, and phenotype of smooth muscle cells (SMCs) interacted with control-PEO and PAT-PEO films were investigated. All control-PEO and PAT-PEO films showed a significant inhibitory effect on the growth of SMCs, with the degree of inhibition strongly dependent on the w/v% of the polymer used. The PAT-PEO coating was produced on the balloons. The integrity of PAT-PEO coating was well maintained without any mechanical defects occurring during balloon inflation or deflation. The drug release studies showed that only 15% of the total PAT loaded was released from the balloons within the initial 1min (typical balloon tracking time), whereas 80% of the PAT was released between 1min and 4min (typical balloon treatment time). Thus, this study demonstrated the use of PEO as an alternate drug delivery system for the balloons. Atherosclerosis is primarily responsible for cardiovascular diseases (CVDs) in millions of
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Fracture characteristics of balloon films
NASA Technical Reports Server (NTRS)
Portanova, Marc A.
1989-01-01
An attempt was made to determine the failure modes of high altitude scientific balloons through an investigation of the fracture characteristics of the thin polyethylene films. Two films were the subject of the evaluation, Winzen Int.'s Stratafilm SF-85 and Raven Industries' Astro-E. Research began with an investigation of the film's cold brittleness point and it's effect on the ultimate strength and elasticity of the polyethylene film. A series of preliminary investigations were conducted to develop an understanding of the material characteristics. The primary focus of this investigation was on the notch sensitivity of the films. Simple stress strain tests were also conducted to enable analysis employing fracture toughness parameters. Studies were conducted on both film types at 23 C (room temperature), -60 C, -90 C, and -120 C.
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NASA Astrophysics Data System (ADS)
Entezam, Mehdi; Aghjeh, Mir Karim Razavi; Ghaffari, Mehdi
2017-02-01
Gel content, mechanical properties and morphology of immiscible PE/EVA blends irradiated by high energy electron beam were studied. The results of gel content measurements showed that the capability of cross-linking of the blend samples increased with an increase of the EVA composition. Also, the gel content for most compositions of the blends displayed a positive deviation from the additive rule. The results of mechanical properties showed that the tensile strength and elongation at break of the samples increased and decreased, respectively, with irradiation dose. On the other hand, the mechanical properties of the irradiated blends also depicted a positive deviation from additive rule contrary to the un-irradiated blends. A synergistic effect observed for the mechanical properties improvement of the irradiated blends and it was attributed to the probable formation of the PE-graft-EVA copolymers at the interface of the blends during the irradiation process. A theoretical analysis revealed that irradiation induced synergistic effect was more significant for EVA-rich blends with weaker interfacial interaction as compared to PE-rich blends. The morphological analysis indicated that the blend morphology was not affected obviously, whereas it was stabilized by irradiation.
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Rtimi, Sami; Nesic, Jelena; Pulgarin, Cesar; Sanjines, Rosendo; Bensimon, Michael; Kiwi, John
2015-02-06
Evidence is presented for radio-frequency plasma pretreatment enhancing the amount and adhesion of TiO2 sputtered on polyester (PES) and on polyethylene (PE) films. Pretreatment is necessary to attain a suitable TiO2 loading leading to an acceptable Escherichia coli reduction kinetics in the dark or under light irradiation for PES-TiO2 and PE-TiO2 samples. The amount of TiO2 on the films was monitored by diffuse reflectance spectroscopy and X-ray fluorescence. X-ray electron spectroscopy shows the lack of accumulation of bacterial residues such as C, N and S during bacterial inactivation since they seem to be rapidly destroyed by TiO2 photocatalysis. Evidence was found for Ti(4+)/Ti(3+) redox catalysis occurring on PES-TiO2 and PE-TiO2 during the bacterial inactivation process. On PE-TiO2 surfaces, Fourier transform infrared spectroscopy (ATR-FTIR) provides evidence for a systematic shift of the na(CH2) stretching vibrations preceding bacterial inactivation within 60 min. The discontinuous IR-peak shifts reflect the increase in the C-H inter-bond distance leading to bond scission. The mechanism leading to E. coli loss of viability on PES-TiO2 was investigated in the dark up to complete bacterial inactivation by monitoring the damage in the bacterial outer cell by transmission electron microscopy. After 30 min, the critical step during the E. coli inactivation commences for dark disinfection on 0.1-5% wt PES-TiO2 samples. The interactions between the TiO2 aggregates and the outer lipopolysaccharide cell wall involve electrostatic effects competing with the van der Waals forces.
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Reconstruction of gas distribution pipelines in MOZG in Poland using PE and PA pipes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Borowicz, W.; Podziemski, T.; Kramek, E.
1996-12-31
MOZG--Warsaw Regional Gas Distribution Company was established in 1856. Now it is one of six gas distribution companies in Poland. Due to steadily increasing safety demands, some of the pipelines will need reconstruction. The majority of the substandard piping is located in urban areas. The company wanted to gain experiences in applying reconstruction technologies using two different plastic materials polyethylene and polyamide. They also wanted to assess the technical and economic practicalities of performing relining processes. A PE project--large diameter polyethylene relining (450 mm) conducted in Warsaw in 1994/95 and PA projects--relining using polyamide pipes, projects conducted in Radom andmore » in Warsaw during 1993 and 1994 are the most interesting and representative for this kind of works. Thanks to the experience obtained whilst carrying out these projects, reconstruction of old gas pipelines has become routine. Now they often use polyethylene relining of smaller diameters and they continue both construction and reconstruction of gas network using PA pipes. This paper presents the accumulated knowledge showing the advantages and disadvantages of applied methods. It describes project design and implementation with details and reports on the necessary preparation work, on site job organization and the most common problems arising during the construction works.« less
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Ahmed, Jasim; Varshney, Sunil K; Auras, Rafael; Hwang, Sung W
2010-10-01
The melt rheology and thermal properties of polylactide (PLA)-based nanocomposite films that were prepared by solvent casting method with L-PLA, polyethylene glycol (PEG), and montmorillonite clay were studied. The neat PLA showed predominantly solid-like behavior (G' > G″) and the complex viscosity (η*) decreased systematically as the temperature increased from 184 to 196 °C. The elastic modulus (G') of PLA/clay blend showed a significant improvement in the magnitude in the melt, while clay concentration was at 6% wt or higher. At similar condition, PEG dramatically reduced dynamic modulii and complex viscosity of PLA/PEG blend as function of concentration. A nanocomposite blend of PLA/PEG/clay (74/20/6) when compared to the neat polymer and PLA/PEG blend exhibited intermediate values of elastic modulus (G') and complex viscosity (η*) with excellent flexibility. Thermal analysis of different clay loading blends indicated that the melting temperature (T(m)) and glass transition temperature (T(g)) remained unaffected irrespective of clay concentration due to immobilization of polymer chain in the clay nanocomposite. PEG incorporation reduced the T(g) and the T(m) of the blends (PLA/PEG and PLA/PEG/clay) significantly, however, crystallinity increased in the similar condition. The transmission electron microscopy (TEM) image of nanocomposite films indicated good compatibility between PLA and PEG, whereas clay was not thoroughly distributed in the PLA matrix and remained as clusters. The percent crystallinity obtained by X-ray was significantly higher than that of differential scanning calorimeter (DSC) data for PLA.
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Waste product profile: Polyethylene terephthalate
DOE Office of Scientific and Technical Information (OSTI.GOV)
Miller, C.
1996-02-01
Polyethylene terephthalate (PET) is a plastic resin used primarily to make bottles. Soft drinks are the primary product packaged in PET. Salad dressing, peanut butter, and other household and consumer products also use PET bottles. PET is also used for film, sheeting for cups and food trays, ovenable trays, and other uses. PET is a relatively new packaging resin, first commercialized in the early `70s. Because it is an ``engineered`` resin, it is more expensive than commodity resins such as high-density polyethylene (HDPE). The primary market for recycled PET is the fiber industry, which uses PET for carpet fiber, sweatersmore » and other clothing, and for other uses. Recycled PET can also be used for food and beverage containers. Export markets, particularly Asian countries, are becoming increasingly important.« less
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Ling, Yichuan; Tian, Yu; Wang, Xi; Wang, Jamie C; Knox, Javon M; Perez-Orive, Fernando; Du, Yijun; Tan, Lei; Hanson, Kenneth; Ma, Biwu; Gao, Hanwei
2016-10-01
Highly bright light-emitting diodes based on solution-processed all-inorganic perovskite thin film are demonstrated. The cesium lead bromide (CsPbBr 3 ) created using a new poly(ethylene oxide)-additive spin-coating method exhibits photoluminescence quantum yield up to 60% and excellent uniformity of electrical current distribution. Using the smooth CsPbBr 3 films as emitting layers, green perovskite-based light-emitting diodes (PeLEDs) exhibit electroluminescent brightness and efficiency above 53 000 cd m -2 and 4%: a new benchmark of device performance for all-inorganic PeLEDs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Analysis of polyethylene wear in plain radiographs
2009-01-01
Background and purpose Two-dimensional computerized radiographic techniques are frequently used to measure in vivo polyethylene (PE) wear after total hip arthroplasty (THA), and several variables in the clinical set-up may influence the amount of wear that is measured. We compared the repeatability and concurrent validity of linear PE wear on plain radiographs using the same software but a different number of radiographs. Methods We used either 1, 2, or 6 anteroposterior (AP) hip radiographs of 11 patients from a clinical THA series with 12 years of follow-up, and measured the PE wear with the software PolyWare 3D Pro. Repeatability within and concurrent validity between the different numbers of radiograph strategies were assessed using limits of agreement (LOAs) and bias. Results Observed median wear (range) in mm was 3.4 (1.6–4.6), 2.3 (0.7–4.9), and 4.0 (2.6–6.2) for the 1-, 2-, and 6-radiograph strategies. For repeatability, no bias (p > 0.41) was observed. LOAs around the bias were ± 0.6, ± 0.4, and ± 1.2 mm for the 1-, 2-, and 6-radiograph strategies. For concurrent validity, a bias (± LOA) between all pairwise comparisons was observed (p < 0.02) with 0.8 mm (± 2.5) between the 1- and 2-radiograph strategies, 1.0 mm (± 2.2) between the 1- and 6-radiograph strategies, and 1.8 mm (± 1.2) between the 2- and 6-radiograph strategies. Interpretation The number of radiographs used for wear measurement with a shadow-casting analysis method on plain AP radiographs influences the amount of linear wear measured. Results of PE wear obtained with PolyWare in studies using a different number of radiographs are not comparable. PMID:19995318
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NASA Astrophysics Data System (ADS)
Švorčík, V.; Chaloupka, A.; Záruba, K.; Král, V.; Bláhová, O.; Macková, A.; Hnatowicz, V.
2009-08-01
Polyethylene (PE) was treated in Ar plasma discharge and then grafted from methanol solution of 1,2-ethanedithiol to enhance adhesion of gold nano-particles or sputtered gold layers. The modified PE samples were either immersed into freshly prepared colloid solution of Au nano-particles or covered by sputtered, 50 nm thick gold nano-layer. Properties of the plasma modified, dithiol grafted and gold coated PE were studied using XPS, UV-VIS, AFM, EPR, RBS methods and nanoindentation. It was shown that the plasma treatment results in degradation of polymer chain, creation of excessive free radicals and conjugated double bonds. After grafting with 1,2-ethanedithiol the concentration of free radicals declined but the concentration of double bonds remained unchanged. Plasma treatment changes PE surface morphology and increases surface roughness too. Another significant change in the surface morphology and roughness was observed after deposition of Au nano-particles. The presence of Au on the sample surface after the coating with Au nano-particles was proved by XPS and RBS methods. Nanoindentation measurements shown that the grafting of plasma activated PE surface with dithiol increases significantly adhesion of sputtered Au nano-layer.
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Nawab, Anjum; Alam, Feroz; Haq, Mohammad Abdul; Haider, Mohammad Samee; Lutfi, Zubala; Kamaluddin, Sheikh; Hasnain, Abid
2018-07-15
In this study mango kernel starch (MKS) based heat sealable pouches were developed for packing of red chili powder. The films were prepared by casting technique using glycerol, sorbitol and 1:1 mixture of glycerol and sorbitol and were sealed. All films showed better heat sealing capacity but glycerol films plasticized exhibited higher seal strength than their counterparts. The red chili powder was packed in the MKS film pouches while commercially available polyethylene (PE) film was used as control. The pungency and color of red chili powder was monitored during six months storage at 40°C. The capsaicinoid content was extracted from the red chili with acetonitrile and evaluated quantitatively using spectrophotometric method. The extractable color was measured by ASTA method using acetone. The results showed significant differences in color and pungency of chili packed in MKS and PE pouches. The highest reduction in capsaicinoid content (pungency) of chili powder was observed in PE pouch (25.9%) while lowest was observed in MKS pouch containing sorbitol (15.7%). Similarly color loss was also highest in chili packed in PE pouch while lowest in MKS-sorbitol pouch. Copyright © 2018 Elsevier B.V. All rights reserved.
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Yamamoto, Y; Sefton, M V
1998-01-01
Poly(ethylene glycol) (PEG) was grafted onto poly(acrylamide-co-vinyl amine) (poly(AM-co-VA)) film using tresylated PEG (TPEG) at 37 degrees C in aqueous buffers (pH 7.4) with a view to surface-modifying microencapsulated mammalian cells. Poly(AM-co-VA) film was synthesized by Hofmann degradation of a cross-linked poly(acrylamide) film. Conversion to vinyl amine on the surface of the film was approximately 50%, but bulk conversion was not observed; surface specificity was thought to be the result of cleavage of aminated polymer chains at the surface due to chain scission. Reaction between primary amine and TPEG gave a graft yield of 2 mol% (based on XPS) with respect to available surface amine groups, equivalent to 54 mol% ethylene oxide based on monomer units. Physical adsorption of non-activated polymer was done under identical conditions as a control and the difference in oxygen content was significant compared to TPEG. The type of buffer agent and buffer concentration did not influence graft yields. This graft reaction, which was completed in as little as 2 h was considered to be mild enough to be used for a surface modification of microcapsules containing cells without affecting their viability. Such a surface modification technique may prove to be a useful means of enhancing the biocompatibility of microcapsules (or any tissue engineering construct) even after cell encapsulation or seeding.
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Localized entrapment of green fluorescent protein within nanostructured polymer films
NASA Astrophysics Data System (ADS)
Ankner, John; Kozlovskaya, Veronika; O'Neill, Hugh; Zhang, Qiu; Kharlampieva, Eugenia
2012-02-01
Protein entrapment within ultrathin polymer films is of interest for applications in biosensing, drug delivery, and bioconversion, but controlling protein distribution within the films is difficult. We report on nanostructured protein/polyelectrolyte (PE) materials obtained through incorporation of green fluorescent protein (GFP) within poly(styrene sulfonate)/poly(allylamine hydrochloride) multilayer films assembled via the spin-assisted layer-by-layer method. By using deuterated GFP as a marker for neutron scattering contrast we have inferred the architecture of the films in both normal and lateral directions. We find that films assembled with a single GFP layer exhibit a strong localization of the GFP without intermixing into the PE matrix. The GFP volume fraction approaches the monolayer density of close-packed randomly oriented GFP molecules. However, intermixing of the GFP with the PE matrix occurs in multiple-GFP layer films. Our results yield new insight into the organization of immobilized proteins within polyelectrolyte matrices and open opportunities for fabrication of protein-containing films with well-organized structure and controllable function, a crucial requirement for advanced sensing applications.
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NASA Astrophysics Data System (ADS)
Mahmoud Nasef, Mohamed; Abbasi, Ali; Ting, T. M.
2014-10-01
A new CO2 adsorbent containing triethylamine (TEA) was prepared by radiation induced grafting of glycidyl methacrylate (GMA) onto polyethylene coated polypropylene (PE-PP) non-woven sheet followed by amination reaction. The degree of grafting (DOG%) was controlled by variation of monomer concentration and absorbed dose. The incorporation of aminated poly(GMA) was investigated by Fourier transform infrared (FTIR) and scanning electron microscope (SEM). The adsorbent with DOG of 350% and amination yield of 60% exhibited CO2 adsorption capacity of 4.52 mol/kg at ambient temperature and pressure.
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Yin, Kezhen; Zhou, Zheng; Schuele, Donald E; Wolak, Mason; Zhu, Lei; Baer, Eric
2016-06-01
Recently, poly(vinylidene fluoride) (PVDF)-based multilayer films have demonstrated enhanced dielectric properties, combining high energy density and high dielectric breakdown strength from the component polymers. In this work, further enhanced dielectric properties were achieved through interface/interphase modulation and biaxial orientation for the poly(ethylene terephthalate)/poly(methyl methacrylate)/poly(vinylidene fluoride-co-hexafluoropropylene) [PET/PMMA/P(VDF-HFP)] three-component multilayer films. Because PMMA is miscible with P(VDF-HFP) and compatible with PET, the interfacial adhesion between PET and P(VDF-HFP) layers should be improved. Biaxial stretching of the as-extruded multilayer films induced formation of highly oriented fibrillar crystals in both P(VDF-HFP) and PET, resulting in improved dielectric properties with respect to the unstretched films. First, the parallel orientation of PVDF crystals reduced the dielectric loss from the αc relaxation in α crystals. Second, biaxial stretching constrained the amorphous phase in P(VDF-HFP) and thus the migrational loss from impurity ions was reduced. Third, biaxial stretching induced a significant amount of rigid amorphous phase in PET, further enhancing the breakdown strength of multilayer films. Due to the synergistic effects of improved interfacial adhesion and biaxial orientation, the PET/PMMA/P(VDF-HFP) 65-layer films with 8 vol % PMMA exhibited optimal dielectric properties with an energy density of 17.4 J/cm(3) at breakdown and the lowest dielectric loss. These three-component multilayer films are promising for future high-energy-density film capacitor applications.
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Morphological characterization of selected balloon films and its effects on balloon performances
NASA Technical Reports Server (NTRS)
Said, Magdi A.
1994-01-01
Morphological characterization of several polyethylene balloon films have been studied using various techniques. The objective is to determine, if any, differentiating structural or morphological features that can be related to the performance of these balloon film materials. The results of the study indicate that the films are composed of either linear low denstiy polyethylene (LLDPE) or low density polyethylene (LDPE). A selective examination of these data imply that films limited degree of branching and larger crystallites size (same % crystallinity) showed good mechanical properties that appear to correlate with their high level of success in balloon flights.
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Assegie, Addisu Alemayehu; Cheng, Ju-Hsiang; Kuo, Li-Ming; Su, Wei-Nien; Hwang, Bing-Joe
2018-03-29
The practical implementation of an anode-free lithium-metal battery with promising high capacity is hampered by dendrite formation and low coulombic efficiency. Most notably, these challenges stem from non-uniform lithium plating and unstable SEI layer formation on the bare copper electrode. Herein, we revealed the homogeneous deposition of lithium and effective suppression of dendrite formation using a copper electrode coated with a polyethylene oxide (PEO) film in an electrolyte comprising 1 M LiTFSI, DME/DOL (1/1, v/v) and 2 wt% LiNO3. More importantly, the PEO film coating promoted the formation of a thin and robust SEI layer film by hosting lithium and regulating the inevitable reaction of lithium with the electrolyte. The modified electrode exhibited stable cycling of lithium with an average coulombic efficiency of ∼100% over 200 cycles and low voltage hysteresis (∼30 mV) at a current density of 0.5 mA cm-2. Moreover, we tested the anode-free battery experimentally by integrating it with an LiFePO4 cathode into a full-cell configuration (Cu@PEO/LiFePO4). The new cell demonstrated stable cycling with an average coulombic efficiency of 98.6% and capacity retention of 30% in the 200th cycle at a rate of 0.2C. These impressive enhancements in cycle life and capacity retention result from the synergy of the PEO film coating, high electrode-electrolyte interface compatibility, stable polar oligomer formation from the reduction of 1,3-dioxolane and the generation of SEI-stabilizing nitrite and nitride upon lithium nitrate reduction. Our result opens up a new route to realize anode-free batteries by modifying the copper anode with PEO to achieve ever more demanding yet safe interfacial chemistry and control of dendrite formation.
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Kowalczyk, Anna; Chyc, Marek; Ryszka, Przemysław; Latowski, Dariusz
2016-06-01
This study presents results of research on isolation new bacteria strain Achromobacter xylosoxidans able to effect on the structure of high-density polyethylene (HDPE), polymer resistant to degradation in environment. New strain of A. xylosoxidans PE-1 was isolated from the soil and identified by analysis of the 16S ribosome subunit coding sequences. The substance to be degraded was HDPE in the form of thin foil films. The foil samples were analyzed with Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) as well as scanning electron microscope (SEM), and the results revealed degradation of chemical structure of HDPE. About 9 % loss of weight was also detected as a result of A. xylosoxidans PE-1 effect on HDPE foil. On the basis of comparative spectral analysis of the raw material before the bacteria treatment and the spectrum from a spectra database, it was assumed that the HDPE was the only source of carbon and energy for the microorganisms. No fillers or other additives used in the plastic processing were observed in HDPE before experiments. This is the first communication showing that A. xylosoxidans is able to modify chemical structure of HDPE, what was observed both on FTIR, in mass reduction of HDPE and SEM analysis. We also observed quite good growth of the bacteria also when the HDPE was the sole carbon source in the medium. These results prove that A. xylosoxidans is an organism worth applying in future HDPE biodegradation studies.
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Yang, Wenguang; Yu, Haibo; Li, Gongxin; Wang, Yuechao; Liu, Lianqing
2016-12-01
Poly(ethylene glycol) diacrylate (PEGDA) is a common hydrogel that has been actively investigated for various tissue engineering applications owing to its biocompatibility and excellent mechanical properties. However, the native PEGDA films are known for their bio-inertness which can hinder cell adhesion, thereby limiting their applications in tissue engineering and biomedicine. Recently, nano composite technology has become a particularly hot topic, and has led to the development of new methods for delivering desired properties to nanomaterials. In this study, we added polystyrene nano-spheres (PS) into a PEGDA solution to synthesize a nano-composite film and evaluated its characteristics. The experimental results showed that addition of the nanospheres to the PEGDA film not only resulted in modification of the mechanical properties and surface morphology but further improved the adhesion of cells on the film. The tensile modulus showed clear dependence on the addition of PS, which enhanced the mechanical properties of the PEGDA-PS film. We attribute the high stiffness of the hybrid hydrogel to the formation of additional cross-links between polymeric chains and the nano-sphere surface in the network. The effect of PS on cell adhesion and proliferation was evaluated in L929 mouse fibroblast cells that were seeded on the surface of various PEGDA-PS films. Cells density increased with a larger PS concentration, and the cells displayed a spreading morphology on the hybrid films, which promoted cell proliferation. Impressively, cellular stiffness could also be modulated simply by tuning the concentration of nano-spheres. Our results indicate that the addition of PS can effectively tailor the physical and biological properties of PEGDA as well as the mechanical properties of cells, with benefits for biomedical and biotechnological applications.
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Balaji, Arunpandian; Jaganathan, Saravana Kumar; Supriyanto, Eko; Muhamad, Ida Idayu; Khudzari, Ahmad Zahran Md
2015-01-01
Developing multifaceted, biocompatible, artificial implants for tissue engineering is a growing field of research. In recent times, several works have been reported about the utilization of biomolecules in combination with synthetic materials to achieve this process. Accordingly, in this study, the ability of an extract obtained from Aloe vera, a commonly used medicinal plant in influencing the biocompatibility of artificial material, is scrutinized using metallocene polyethylene (mPE). The process of coating dense fibrous Aloe vera extract on the surface of mPE was carried out using microwaves. Then, several physicochemical and blood compatibility characterization experiments were performed to disclose the effects of corresponding surface modification. The Fourier transform infrared spectrum showed characteristic vibrations of several active constituents available in Aloe vera and exhibited peak shifts at far infrared regions due to aloe-based mineral deposition. Meanwhile, the contact angle analysis demonstrated a drastic increase in wettability of coated samples, which confirmed the presence of active components on glazed mPE surface. Moreover, the bio-mimic structure of Aloe vera fibers and the influence of microwaves in enhancing the coating characteristics were also meticulously displayed through scanning electron microscopy micrographs and Hirox 3D images. The existence of nanoscale roughness was interpreted through high-resolution profiles obtained from atomic force microscopy. And the extent of variations in irregularities was delineated by measuring average roughness. Aloe vera-induced enrichment in the hemocompatible properties of mPE was established by carrying out in vitro tests such as activated partial thromboplastin time, prothrombin time, platelet adhesion, and hemolysis assay. In conclusion, the Aloe vera-glazed mPE substrate was inferred to attain desirable properties required for multifaceted biomedical implants. PMID:26425089
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Balaji, Arunpandian; Jaganathan, Saravana Kumar; Supriyanto, Eko; Muhamad, Ida Idayu; Khudzari, Ahmad Zahran Md
2015-01-01
Developing multifaceted, biocompatible, artificial implants for tissue engineering is a growing field of research. In recent times, several works have been reported about the utilization of biomolecules in combination with synthetic materials to achieve this process. Accordingly, in this study, the ability of an extract obtained from Aloe vera, a commonly used medicinal plant in influencing the biocompatibility of artificial material, is scrutinized using metallocene polyethylene (mPE). The process of coating dense fibrous Aloe vera extract on the surface of mPE was carried out using microwaves. Then, several physicochemical and blood compatibility characterization experiments were performed to disclose the effects of corresponding surface modification. The Fourier transform infrared spectrum showed characteristic vibrations of several active constituents available in Aloe vera and exhibited peak shifts at far infrared regions due to aloe-based mineral deposition. Meanwhile, the contact angle analysis demonstrated a drastic increase in wettability of coated samples, which confirmed the presence of active components on glazed mPE surface. Moreover, the bio-mimic structure of Aloe vera fibers and the influence of microwaves in enhancing the coating characteristics were also meticulously displayed through scanning electron microscopy micrographs and Hirox 3D images. The existence of nanoscale roughness was interpreted through high-resolution profiles obtained from atomic force microscopy. And the extent of variations in irregularities was delineated by measuring average roughness. Aloe vera-induced enrichment in the hemocompatible properties of mPE was established by carrying out in vitro tests such as activated partial thromboplastin time, prothrombin time, platelet adhesion, and hemolysis assay. In conclusion, the Aloe vera-glazed mPE substrate was inferred to attain desirable properties required for multifaceted biomedical implants.
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Cascioferro, Alessandro; Donà, Valentina; Delogu, Giovanni; Palù, Giorgio; Bitter, Wilbert; Manganelli, Riccardo
2011-01-01
PE are peculiar exported mycobacterial proteins over-represented in pathogenic mycobacterial species. They are characterized by an N-terminal domain of about 110 amino acids (PE domain) which has been demonstrated to be responsible for their export and localization. In this paper, we characterize the PE domain of PE_PGRS33 (PERv1818c), one of the best characterized PE proteins. We constructed several mutated proteins in which portions of the PE domain were deleted or subjected to defined mutations. These proteins were expressed in different mycobacterial species and their localization was characterized. We confirmed that the PE domain is essential for PE_PGRS33 surface localization, and demonstrated that a PE domain lacking its first 30 amino acids loses its function. However, single amino acid substitutions in two regions extremely well conserved within the N-terminal domain of all PE proteins had some effect on the stability of PE_PGRS33, but not on its localization. Using Mycobacterium marinum we could show that the type VII secretion system ESX-5 is essential for PE_PGRS33 export. Moreover, in M. marinum, but not in Mycobacterium bovis BCG and in Mycobacterium tuberculosis, the PE domain of PE_PGRS33 is processed and secreted into the culture medium when expressed in the absence of the PGRS domain. Finally, using chimeric proteins in which different portions of the PERv1818c domain were fused to the N-terminus of the green fluorescent protein, we could hypothesize that the first 30 amino acids of the PE domain contain a sequence that allows protein translocation. PMID:22110736
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Electric Charge Accumulation in Polar and Non-Polar Polymers under Electron Beam Irradiation
NASA Astrophysics Data System (ADS)
Nagasawa, Kenichiro; Honjoh, Masato; Takada, Tatsuo; Miyake, Hiroaki; Tanaka, Yasuhiro
The electric charge accumulation under an electron beam irradiation (40 keV and 60 keV) was measured by using the pressure wave propagation (PWP) method in the dielectric insulation materials, such as polar polymeric films (polycarbonate (PC), polyethylene-naphthalate (PEN), polyimide (PI), and polyethylene-terephthalate (PET)) and non-polar polymeric films (polystyrene (PS), polypropylene (PP), polyethylene (PE) and polytetrafluoroethylene (PTFE)). The PE and PTFE (non-polar polymers) showed the properties of large amount of electric charge accumulation over 50 C/m3 and long saturation time over 80 minutes. The PP and PS (non-polar polymer) showed the properties of middle amount of charge accumulation about 20 C/m3 and middle saturation time about 1 to 20 minutes. The PC, PEN, PI and PET (polar polymers) showed the properties of small amount of charge accumulation about 5 to 20 C/m3 and within short saturation time about 1.0 minutes. This paper summarizes the relationship between the properties of charge accumulation and chemical structural formula, and compares between the electro static potential distribution with negative charged polymer and its chemical structural formula.
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Wang, Zhenwen; Zhao, Jun; Chen, Min; Yang, Minhao; Tang, Luyang; Dang, Zhi-Min; Chen, Fenghua; Huang, Miaoming; Dong, Xia
2014-11-26
In this work, electrically and thermally actuated triple shape memory polymers (SMPs) of chemically cross-linked polycyclooctene (PCO)-multiwalled carbon nanotube (MWCNT)/polyethylene (PE) nanocomposites with co-continuous structure and selective distribution of fillers in PCO phase are prepared. We systematically studied not only the microstructure including morphology and fillers' selective distribution in one phase of the PCO/PE blends, but also the macroscopic properties including thermal, mechanical, and electrical properties. The co-continuous window of the immiscible PCO/PE blends is found to be the volume fraction of PCO (vPCO) of ca. 40-70 vol %. The selective distribution of fillers in one phase of co-continuous blends is obtained by a masterbatch technique. The prepared triple SMP materials show pronounced triple shape memory effects (SMEs) on the dynamic mechanical thermal analysis (DMTA) and the visual observation by both thermal and electric actuations. Such polyolefin samples with well-defined microstructure, electrical actuation, and triple SMEs might have potential applications as, for example, multiple autochoke elements for engines, self-adjusting orthodontic wires, and ophthalmic devices.
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Effects of 1 MeV electrons on the deformation mechanisms of polyethylene/carbon nanotube composites
NASA Astrophysics Data System (ADS)
Yang, Jianqun; Zhang, Xiaodong; Liu, Chaoming; Li, Xingji; Li, Hongxia; Ma, Guoliang; Tian, Feng
2017-10-01
Polymer nano-composites, especially in polyethylene (PE)/carbon nanotube (CNT) composites can be employed as radiation shielding and structural materials in space. When the PE/CNT composites are used in space, it is easy to suffer from radiation damage caused by charged particles. However, few studies about deformation mechanisms of the composites exposed to electron become available so far. In this paper, mutiwalled carbon nanotubes (MWCNTs) were incorporated into low density polyethylene (LDPE) with MWCNT loadings concentrations of 0.1 wt%. The structural evolution during uniaxial tensile deformation of the LDPE/0.1% MWCNT composites before and after 1 MeV electrons were investigated by means of a small angle X-ray scattering (SAXS) and wide angle X-ray diffraction (WAXD). Experimental results show that 1 MeV electrons obviously increase the ultimate tensile strength of the LDPE/MWCNT composites. From SAXS and WAXD analyses, it is shown that 1 MeV electrons inhibit the disintegration and the rotation of the lamellae, and slow down the formation of the new crystals. It is concluded that the intense interaction between MWCNTs and LDPE matrix and the crosslinking strengthening generated by 1 MeV electrons is the dominant reason for the changes of the deformation behaviors of LDPE.
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NASA Astrophysics Data System (ADS)
Cai, Lu; Lv, Wenzhen; Zhu, Hong; Xu, Qun
2016-07-01
The mechanism of the adsorption of pyrene-polyethylene (Py-PE) onto ultrathin single-walled carbon nanotube (SWNT) was studied by using all-atom molecular dynamics (MD) simulations. We found that solvent polarity and pyrene group are two critical factors in the Py-PE decoration on ultrathin SWNT. Combined MD simulations with free energy calculations, our results indicate that larger solvent polarity can decrease the contribution of conformation entropy, but contributes little to the interaction energy, moreover, larger SWNT diameter can decrease the contribution of conformation entropy but lead to the increasing of the interaction energy. In polar organic solvent (N, N-Dimethylacetamide), the pyrene group plays a key role in the adsorption of Py-PE onto ultrathin SWNT, not only facilitates the spontaneous adsorption of Py-PE onto ultrathin SWNT, but also helps to form compact structure between themselves in the final adsorption states. While in aqueous solution, pyrene group no longer works as an anchor, but still affects a lot to the final adsorption conformation. Our present work provides detailed theoretical clue to understand the noncovalent interaction between aromatic segment appended polymer and ultrathin SWNT, and helps to explore the potential application of ultrathin SWNT in the fields of hybrid material, biomedical and electronic materials.
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Wang, H; Chen, D; Yuan, G; Ma, X; Dai, X
2013-02-01
In this work, the morphological characteristics of waste polyethylene (PE)/polypropylene (PP) plastics during their pyrolysis process were investigated, and based on their basic image changing patterns representative morphological signals describing the pyrolysis stages were obtained. PE and PP granules and films were used as typical plastics for testing, and influence of impurities was also investigated. During pyrolysis experiments, photographs of the testing samples were taken sequentially with a high-speed infrared camera, and the quantitative parameters that describe the morphological characteristics of these photographs were explored using the "Image Pro Plus (v6.3)" digital image processing software. The experimental results showed that plastics pyrolysis involved four stages: melting, two stages of decomposition which are characterized with bubble formation caused by volatile evaporating, and ash deposition; and each stage was characterized with its own phase changing behaviors and morphological features. Two stages of decomposition are the key step of pyrolysis since they took up half or more of the reaction time; melting step consumed another half of reaction time in experiments when raw materials were heated up from ambient temperatures; and coke-like deposition appeared as a result of decomposition completion. Two morphological signals defined from digital image processing, namely, pixel area of the interested reaction region and bubble ratio (BR) caused by volatile evaporating were found to change regularly with pyrolysis stages. In particular, for all experimental scenarios with plastics films and granules, the BR curves always exhibited a slowly drop as melting started and then a sharp increase followed by a deep decrease corresponding to the first stage of intense decomposition, afterwards a second increase - drop section corresponding to the second stage of decomposition appeared. As ash deposition happened, the BR dropped to zero or very low
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Electrospun Polyaniline/Polyethylene Oxide Nanofiber Field Effect Transistor
NASA Technical Reports Server (NTRS)
Pinto, N. J.; Johnson, A. T.; MacDiarmid, A. G.; Mueller, C. H.; Theofylaktos, N.; Robinson, D. C.; Miranda, F. A.
2003-01-01
We report on the observation of field effect transistor (FET) behavior in electrospun camphorsulfonic acid doped polyaniline(PANi)/polyethylene oxide(PE0) nanofibers. Saturation channel currents are observed at surprisingly low source/drain voltages. The hole mobility in the depletion regime is 1.4 x 10(exp -4) sq cm/V s while the 1-D charge density (at zero gate bias) is calculated to be approximately 1 hole per 50 two-ring repeat units of polyaniline, consistent with the rather high channel conductivity (approx. 10(exp -3) S/cm). Reducing or eliminating the PEO content in the fiber is expected to enhance device parameters. Electrospinning is thus proposed as a simple method of fabricating 1-D polymer FET's.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Xie, Jiazhuo; Zhang, Kun; Zhao, Qinghua
Novel LDH intercalated with organic aliphatic long-chain anion was large-scale synthesized innovatively by high-energy ball milling in one pot. The linear low density polyethylene (LLDPE)/layered double hydroxides (LDH) composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties were fabricated by melt blending and blowing process. FT IR, XRD, SEM results show that LDH particles were dispersed uniformly in the LLDPE composite films. Particularly, LLDPE composite film with 1% LDH exhibited the optimal performance among all the composite films with a 60.36% enhancement in the water vapor barrier property and a 45.73 °C increase in themore » temperature of maximum mass loss rate compared with pure LLDPE film. Furthermore, the improved infrared absorbance (1180–914 cm{sup −1}) of LLDPE/LDH films revealed the significant enhancement of heat retention. Therefore, this study prompts the application of LLDPE/LDH films as agricultural films with superior heat retention. - Graphical abstract: The fabrication process of LLDPE/LDH composite films. - Highlights: • LDH with basal spacing of 4.07 nm was synthesized by high-energy ball milling. • LLDPE composite films with homogeneous LDH dispersion were fabricated. • The properties of LLDPE/LDH composite films were improved. • LLDPE/LDH composite films show superior heat retention property.« less
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Hsiao, An-En; Tsai, Shu-Ya; Hsu, Mei-Wen; Chang, Shinn-Jen
2012-05-06
We dispersed the non-covalent functionalization of multi-walled carbon nanotubes (CNTs) with a polymer dispersant and obtained a powder of polymer-wrapped CNTs. The UV-vis absorption spectrum was used to investigate the optimal weight ratio of the CNTs and polymer dispersant. The powder of polymer-wrapped CNTs had improved the drawbacks of CNTs of being lightweight and difficult to process, and it can re-disperse in a solvent. Then, we blended the polymer-wrapped CNTs and polyethylene (PE) by melt-mixing and produced a conductive masterbatch and CNT/PE composites. The polymer-wrapped CNTs showed lower surface resistivity in composites than the raw CNTs. The scanning electron microscopy images also showed that the polymer-wrapped CNTs can disperse well in composites than the raw CNTs.
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Chytiri, S D; Badeka, A V; Riganakos, K A; Kontominas, M G
2010-04-01
The aim was to study the effect of electron-beam irradiation on the production of radiolysis products and sensory changes in experimental high-barrier packaging films composed of polyamide (PA), ethylene-vinyl alcohol (EVOH) and low-density polyethylene (LDPE). Films contained a middle buried layer of recycled LDPE, while films containing 100% virgin LDPE as the middle buried layer were taken as controls. Irradiation doses ranged between zero and 60 kGy. Generally, a large number of radiolysis products were produced during electron-beam irradiation, even at the lower absorbed doses of 5 and 10 kGy (approved doses for food 'cold pasteurization'). The quantity of radiolysis products increased with irradiation dose. There were no significant differences in radiolysis products identified between samples containing a recycled layer of LDPE and those containing virgin LDPE (all absorbed doses), indicating the 'functional barrier' properties of external virgin polymer layers. Sensory properties (mainly taste) of potable water were affected after contact with irradiated as low as 5 kGy packaging films. This effect increased with increasing irradiation dose.
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Li, Jie; Lin, Yue; Yao, Hehua; Yuan, Changfu; Liu, Jin
2014-07-01
A tunable polysiloxane thin-film electrolyte for all-solid-state lithium-ion batteries was developed. The polysiloxane was synthesized by hydrosilylation of polymethylhydrosiloxane with cyclic [(allyloxy)methyl]ethylene ester carbonic acid and vinyl tris(2-methoxyethoxy)silane. (1) H NMR spectroscopy and gel-permeation chromatography demonstrated that the bifunctional groups of the cyclic propylene carbonate (PC) and combed poly(ethylene oxide) (PEO) were well grafted on the polysiloxane. At PC/PEO=6:4, the polysiloxane-based electrolyte had an ionic conductivity of 1.55 × 10(-4) and 1.50 × 10(-3) S cm(-1) at 25 and 100 °C, respectively. The LiFePO4 /Li batteries fabricated with the thin-film electrolyte presented excellent cycling performance in the temperature range from 25 to 100 °C with an initial discharge capacity at a rate of 1 C of 88.2 and 140 mA h g(-1) at 25 and 100 °C, respectively. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Coarse-grained modeling of polyethylene melts: Effect on dynamics
Peters, Brandon L.; Salerno, K. Michael; Agrawal, Anupriya; ...
2017-05-23
The distinctive viscoelastic behavior of polymers results from a coupled interplay of motion on multiple length and time scales. Capturing the broad time and length scales of polymer motion remains a challenge. Using polyethylene (PE) as a model macromolecule, we construct coarse-grained (CG) models of PE with three to six methyl groups per CG bead and probe two critical aspects of the technique: pressure corrections required after iterative Boltzmann inversion (IBI) to generate CG potentials that match the pressure of reference fully atomistic melt simulations and the transferability of CG potentials across temperatures. While IBI produces nonbonded pair potentials thatmore » give excellent agreement between the atomistic and CG pair correlation functions, the resulting pressure for the CG models is large compared with the pressure of the atomistic system. We find that correcting the potential to match the reference pressure leads to nonbonded interactions with much deeper minima and slightly smaller effective bead diameter. However, simulations with potentials generated by IBI and pressure-corrected IBI result in similar mean-square displacements (MSDs) and stress autocorrelation functions G( t) for PE melts. While the time rescaling factor required to match CG and atomistic models is the same for pressure- and non-pressure-corrected CG models, it strongly depends on temperature. Furthermore, transferability was investigated by comparing the MSDs and stress autocorrelation functions for potentials developed at different temperatures.« less
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Coarse-grained modeling of polyethylene melts: Effect on dynamics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Peters, Brandon L.; Salerno, K. Michael; Agrawal, Anupriya
The distinctive viscoelastic behavior of polymers results from a coupled interplay of motion on multiple length and time scales. Capturing the broad time and length scales of polymer motion remains a challenge. Using polyethylene (PE) as a model macromolecule, we construct coarse-grained (CG) models of PE with three to six methyl groups per CG bead and probe two critical aspects of the technique: pressure corrections required after iterative Boltzmann inversion (IBI) to generate CG potentials that match the pressure of reference fully atomistic melt simulations and the transferability of CG potentials across temperatures. While IBI produces nonbonded pair potentials thatmore » give excellent agreement between the atomistic and CG pair correlation functions, the resulting pressure for the CG models is large compared with the pressure of the atomistic system. We find that correcting the potential to match the reference pressure leads to nonbonded interactions with much deeper minima and slightly smaller effective bead diameter. However, simulations with potentials generated by IBI and pressure-corrected IBI result in similar mean-square displacements (MSDs) and stress autocorrelation functions G( t) for PE melts. While the time rescaling factor required to match CG and atomistic models is the same for pressure- and non-pressure-corrected CG models, it strongly depends on temperature. Furthermore, transferability was investigated by comparing the MSDs and stress autocorrelation functions for potentials developed at different temperatures.« less
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RS3PE: Clinical and Research Development.
Li, Hongbin; Altman, Roy D; Yao, Qingping
2015-08-01
Remitting seronegative symmetrical synovitis with pitting edema or RS3PE is a rare elderly-onset rheumatic syndrome. Although there are overlapping clinical manifestations between RS3PE, elderly-onset rheumatoid arthritis, and polymyalgia rheumatica, RS3PE has distinct characteristics. RS3PE can be associated with neoplasia and various rheumatic conditions, suggesting that it may be heterogeneous, and is considered as a paraneoplastic rheumatic disease. The pathogenesis of RS3PE may involve vascular endothelial growth factor and infection in RS3PE based upon limited data. Patients with RS3PE without concomitant malignancy respond well to small doses of glucocorticoids and carry good prognosis.
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Porous structure, permeability, and mechanical properties of polyolefin microporous films
NASA Astrophysics Data System (ADS)
Elyashevich, G. K.; Kuryndin, I. S.; Lavrentyev, V. K.; Bobrovsky, A. Yu.; Bukošek, V.
2012-09-01
Microporous films of polyolefins, namely, polyethylene and polypropylene, have been prepared using the process based on the extrusion of the melt with the subsequent annealing, uniaxial extension, and thermal fixation. The influence of the conditions used for preparation of the films on their morphology, porosity, number and sizes of through-flow channels, and mechanical properties has been investigated. It has been found that a significant influence on the characteristics of the porous structure of the films is exerted by the degree of orientation of the melt at extrusion, the annealing temperature, and the degree of uniaxial extension of the films. The threshold values of these parameters, at which through-flow channels are formed in the films, have been determined. It has been shown using filtration porosimetry that polyethylene films have a higher permeability to liquids as compared to the polypropylene samples (240 and 180 L/(m2 h atm), respectively). The porous structure of the polyethylene films is characterized by larger sizes of through pores than those of the polypropylene samples (the average pore sizes are 210 and 160 nm, respectively), whereas the polypropylene films contain a larger number of through-flow channels.
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Helical instability in film blowing process: Analogy to buckling instability
NASA Astrophysics Data System (ADS)
Lee, Joo Sung; Kwon, Ilyoung; Jung, Hyun Wook; Hyun, Jae Chun
2017-12-01
The film blowing process is one of the most important polymer processing operations, widely used for producing bi-axially oriented film products in a single-step process. Among the instabilities observed in this film blowing process, i.e., draw resonance and helical motion occurring on the inflated film bubble, the helical instability is a unique phenomenon portraying the snake-like undulation motion of the bubble, having the period on the order of few seconds. This helical instability in the film blowing process is commonly found at the process conditions of a high blow-up ratio with too low a freezeline position and/or too high extrusion temperature. In this study, employing an analogy to the buckling instability for falling viscous threads, the compressive force caused by the pressure difference between inside and outside of the film bubble is introduced into the simulation model along with the scaling law derived from the force balance between viscous force and centripetal force of the film bubble. The simulation using this model reveals a close agreement with the experimental results of the film blowing process of polyethylene polymers such as low density polyethylene and linear low density polyethylene.
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Rodgers, K; Cohn, D; Hotovely, A; Pines, E; Diamond, M P; diZerega, G
1998-03-01
To assess the efficacy of bioresorbable films consisting of various polyethylene glycol 6000 and polylactic acid block copolymers on the formation and reformation of adhesions in rabbit models of adhesion development between the sidewall to the adjacent cecum and bowel. The composition of the different polymers was expressed by the number of monomeric units in the block, namely, ethylene oxide (EO) and lactic acid (LA), respectively. Studies of the efficacy of EO/LA films were conducted in rabbit sidewall adhesion formation studies in the presence and absence of blood and in rabbit adhesion reformation studies. REPEL (Life Medical Sciences, Edison, NJ), a film of EO/LA ratio 3.0 manufactured under commercial conditions, was also tested in these animal models. University-based laboratory. New Zealand white rabbits. Placement of films of various EO/LA ratios at the site of injury to the parietal peritoneum. Adhesion formation and reformation. Films of various EO/LA ratios, Seprafilm (Genzyme, Cambridge, MA) and Interceed (Johnson and Johnson Medical, Arlington, TX) placed over an area of excised sidewall at the time of initial injury were highly efficacious in the prevention of adhesion formation. A film of EO/LA ratio 3.7, in contrast with Interceed, was also shown to maintain maximal efficacy in the reduction of adhesion formation in the presence of blood. Further, a film of EO/LA ratio 3.0 produced under commercial conditions, REPEL, was highly efficacious in reducing adhesion development in the rabbit models of adhesion and reformation. These studies suggest that bioresorbable EO/LA films reduced adhesion development in rabbit models of adhesion formation and reformation.
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NASA Astrophysics Data System (ADS)
Das, Sayantan; Alford, T. L.
2013-06-01
Silver doped cupric oxide thin films are prepared on polyethylene naphthalate (flexible polymer) substrates. Thin films Ag-doped CuO are deposited on the substrate by co-sputtering followed by microwave assisted oxidation of the metal films. The low temperature tolerance of the polymer substrates led to the search for innovative low temperature processing techniques. Cupric oxide is a p-type semiconductor with an indirect band gap and is used as selective absorption layer solar cells. X-ray diffraction identifies the CuO phases. Rutherford backscattering spectrometry measurements confirm the stoichiometry of each copper oxide formed. The surface morphology is determined by atomic force microscopy. The microstructural properties such as crystallite size and the microstrain for (-111) and (111) planes are calculated and discussed. Incorporation of Ag led to the lowering of band gap in CuO. Consequently, it is determined that Ag addition has a strong effect on the structural, morphological, surface, and optical properties of CuO grown on flexible substrates by microwave annealing. Tauc's plot is used to determine the optical band gap of CuO and Ag doped CuO films. The values of the indirect and direct band gap for CuO are found to be 2.02 eV and 3.19 eV, respectively.
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Torres-Arreola, Wilfrido; Soto-Valdez, Herlinda; Peralta, Elizabeth; Cardenas-López, José Luis; Ezquerra-Brauer, Josafat Marina
2007-07-25
Fresh sierra fish (Scomberomorus sierra) fillets were packed in low-density polyethylene films with butylated hydroxytoluene (BHT-LDPE) added. Fillets packed in LDPE with no BHT were used as controls (LDPE). The packed fillets were stored at -25 degrees C for 120 days in which the film released 66.5% of the antioxidant. The influence of the antioxidant on lipid and protein quality, lipid oxidation, muscle structure changes, and shear-force resistance was recorded. As compared to LDPE films, fillets packed in BHT-LDPE films showed lower lipid oxidation, thiobarbituric acid values (4.20 +/- 0.52 vs 11.95 +/- 1.06 mg malonaldehyde/kg), peroxide values (7.20 +/- 1.38 vs 15.15 +/- 1.48 meq/kg), and free fatty acids (7.98 +/- 0.43 vs 11.83 +/- 1.26% of oleic acid). Fillets packed in BHT-LDPE films showed less tissue damage and lost less firmness than fillets packed in LDPE. A significant relationship between lipid oxidation and texture was detected (R2 adjusted, 0.70-0.73). BHT-LDPE films may be used not only to prevent lipid oxidation but also to minimize protein damage to prolong the shelf life of sierra fish.
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NASA Astrophysics Data System (ADS)
Reznickova, A.; Kolska, Z.; Orendac, M.; Cizmar, E.; Sajdl, P.; Svorcik, V.
2016-08-01
This study focuses on high density polyethylene (HDPE) activated by Ar plasma treatment, subsequently grafted with copper sulfonated phthalocyanine (CuPc) especially pointing out to the surface and magnetic properties of those composites. Properties of pristine PE and their plasma treated counterparts were studied by different experimental techniques: X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy, zeta potential and by electron spin resonance (ESR). XPS analysis confirmed the successful grafting of phthalocyanine. The highest absorption was found for the sample grafted with bCuPc for 1 h. Electrokinetic analysis also confirmed the plasma treatment and also subsequent CuPc grafting influence significantly the surface chemistry and charge. These results correspond well with XPS determination. ESR studies confirmed the presence of CuPc grafted on HDPE. It was found, that grafting is mediated by magnetically inactive functional groups, rather than radicals. Magnetic properties of CuPc do not seem to change significantly after grafting CuPc on polyethylene surface.
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Zanini, Filippo; Carmignato, Simone
2017-01-01
More than 60.000 hip arthroplasty are performed every year in Italy. Although Ultra-High-Molecular-Weight-Polyethylene remains the most used material as acetabular cup, wear of this material induces over time in vivo a foreign-body response and consequently osteolysis, pain, and the need of implant revision. Furthermore, oxidative wear of the polyethylene provoke several and severe failures. To solve these problems, highly cross-linked polyethylene and Vitamin-E-stabilized polyethylene were introduced in the last years. In in vitro experiments, various efforts have been made to compare the wear behavior of standard PE and vitamin-E infused liners. In this study we compared the in vitro wear behavior of two different configurations of cross-linked polyethylene (with and without the add of Vitamin E) vs. the standard polyethylene acetabular cups. The aim of the present study was to validate a micro X-ray computed tomography technique to assess the wear of different commercially available, polyethylene’s acetabular cups after wear simulation; in particular, the gravimetric method was used to provide reference wear values. The agreement between the two methods is documented in this paper. PMID:28107468
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Interaction of High Flash Point Electrolytes and PE-Based Separators for Li-Ion Batteries
Hofmann, Andreas; Kaufmann, Christoph; Müller, Marcus; Hanemann, Thomas
2015-01-01
In this study, promising electrolytes for use in Li-ion batteries are studied in terms of interacting and wetting polyethylene (PE) and particle-coated PE separators. The electrolytes are characterized according to their physicochemical properties, where the flow characteristics and the surface tension are of particular interest for electrolyte–separator interactions. The viscosity of the electrolytes is determined to be in a range of η = 4–400 mPa∙s and surface tension is finely graduated in a range of γL = 23.3–38.1 mN∙m−1. It is verified that the technique of drop shape analysis can only be used in a limited matter to prove the interaction, uptake and penetration of electrolytes by separators. Cell testing of Li|NMC half cells reveals that those cell results cannot be inevitably deduced from physicochemical electrolyte properties as well as contact angle analysis. On the other hand, techniques are more suitable which detect liquid penetration into the interior of the separator. It is expected that the results can help fundamental researchers as well as users of novel electrolytes in current-day Li-ion battery technologies for developing and using novel material combinations. PMID:26343636
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2012-01-01
We dispersed the non-covalent functionalization of multi-walled carbon nanotubes (CNTs) with a polymer dispersant and obtained a powder of polymer-wrapped CNTs. The UV–vis absorption spectrum was used to investigate the optimal weight ratio of the CNTs and polymer dispersant. The powder of polymer-wrapped CNTs had improved the drawbacks of CNTs of being lightweight and difficult to process, and it can re-disperse in a solvent. Then, we blended the polymer-wrapped CNTs and polyethylene (PE) by melt-mixing and produced a conductive masterbatch and CNT/PE composites. The polymer-wrapped CNTs showed lower surface resistivity in composites than the raw CNTs. The scanning electron microscopy images also showed that the polymer-wrapped CNTs can disperse well in composites than the raw CNTs. PMID:22559082
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NASA Astrophysics Data System (ADS)
Kirchheim, Dennis; Jaritz, Montgomery; Mitschker, Felix; Gebhard, Maximilian; Brochhagen, Markus; Hopmann, Christian; Böke, Marc; Devi, Anjana; Awakowicz, Peter; Dahlmann, Rainer
2017-03-01
Gas transport mechanisms through plastics are usually described by the temperature-dependent Arrhenius-model and compositions of several plastic layers are represented by the CLT. When it comes to thin films such as plasma-enhanced chemical vapour deposition (PE-CVD) or plasma-enhanced atomic layer deposition (PE-ALD) coatings on substrates of polymeric material, a universal model is lacking. While existing models describe diffusion through defects, these models presume that permeation does not occur by other means of transport mechanisms. This paper correlates the existing transport models with data from water vapour transmission experiments.
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Gao, Pei; Zhang, Xiangyu; Wang, Hongzhi; Zhang, Qinghong
2016-01-01
Calcium phosphate nanoparticles are safe and effective delivery vehicles for small interfering RNA (siRNA), as a result of their excellent biocompatibility. In this work, mPEG-PE (polyethylene glycol-L-α-phosphatidylethanolamine) was synthesized and used to prepare nanoparticles composed of mPEG-PE and calcium phosphate for siRNA delivery. Calcium phosphate and mPEG-PE formed the stable hybrid nanoparticles through self-assembly resulting from electrostatic interaction in water. The average size of the hybrid nanoparticles was approximately 53.2 nm with a negative charge of approximately −16.7 mV, which was confirmed by dynamic light scattering (DLS) measurements. The nanoparticles exhibited excellent stability in serum and could protect siRNA from ribonuclease (RNase) degradation. The cellular internalization of siRNA-loaded nanoparticles was evaluated in SMMC-7721 cells using a laser scanning confocal microscope (CLSM) and flow cytometry. The hybrid nanoparticles could efficiently deliver siRNA to cells compared with free siRNA. Moreover, the in vivo distribution of Cy5-siRNA-loaded hybrid nanoparticles was observed after being injected into tumor-bearing nude mice. The nanoparticles concentrated in the tumor regions through an enhanced permeability and retention (EPR) effect based on the fluorescence intensities of tissue distribution. A safety evaluation of the nanoparticles was performed both in vitro and in vivo demonstrating that the hybrid nanoparticle delivery system had almost no toxicity. These results indicated that the mPEG-PE/CaP hybrid nanoparticles could be a stable, safe and promising siRNA nanocarrier for anticancer therapy. PMID:26625203
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Gao, Pei; Zhang, Xiangyu; Wang, Hongzhi; Zhang, Qinghong; Li, He; Li, Yaogang; Duan, Yourong
2016-01-19
Calcium phosphate nanoparticles are safe and effective delivery vehicles for small interfering RNA (siRNA), as a result of their excellent biocompatibility. In this work, mPEG-PE (polyethylene glycol-L-α-phosphatidylethanolamine) was synthesized and used to prepare nanoparticles composed of mPEG-PE and calcium phosphate for siRNA delivery. Calcium phosphate and mPEG-PE formed the stable hybrid nanoparticles through self-assembly resulting from electrostatic interaction in water. The average size of the hybrid nanoparticles was approximately 53.2 nm with a negative charge of approximately -16.7 mV, which was confirmed by dynamic light scattering (DLS) measurements. The nanoparticles exhibited excellent stability in serum and could protect siRNA from ribonuclease (RNase) degradation. The cellular internalization of siRNA-loaded nanoparticles was evaluated in SMMC-7721 cells using a laser scanning confocal microscope (CLSM) and flow cytometry. The hybrid nanoparticles could efficiently deliver siRNA to cells compared with free siRNA. Moreover, the in vivo distribution of Cy5-siRNA-loaded hybrid nanoparticles was observed after being injected into tumor-bearing nude mice. The nanoparticles concentrated in the tumor regions through an enhanced permeability and retention (EPR) effect based on the fluorescence intensities of tissue distribution. A safety evaluation of the nanoparticles was performed both in vitro and in vivo demonstrating that the hybrid nanoparticle delivery system had almost no toxicity. These results indicated that the mPEG-PE/CaP hybrid nanoparticles could be a stable, safe and promising siRNA nanocarrier for anticancer therapy.
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Development of a Remote External Repair Tool for Damaged or Defective Polyethylene Pipe
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kenneth H. Green; Willie E. Rochefort; Nick Wannenmacher
2006-06-30
Current procedures for repairing polyethylene (PE) gas pipe require excavation, isolation, and removal of the damaged section of pipe followed by fusing a new section of pipe into place. These techniques are costly and very disruptive. An alternative repair method was developed at Timberline Tool with support from Oregon State University (OSU) and funding by the U. S. Department of Energy National Energy Technology Laboratory (DOE/NETL). This project was undertaken to design, develop and test a tool and method for repairing damaged PE pipe remotely and externally in situ without squeezing off the flow of gas, eliminating the need formore » large-scale excavations. Through an iterative design and development approach, a final engineered prototype was developed that utilizes a unique thermo-chemical and mechanical process to apply a permanent external patch to repair small nicks, gouges and punctures under line pressure. The project identified several technical challenges during the design and development process. The repair tool must be capable of being installed under live conditions and operate in an 18-inch keyhole. This would eliminate the need for extensive excavations thus reducing the cost of the repair. Initially, the tool must be able to control the leak by encapsulating the pipe and apply slight pressure at the site of damage. Finally, the repair method must be permanent at typical operating pressures. The overall results of the project have established a permanent external repair method for use on damaged PE gas pipe in a safe and cost-effective manner. The engineered prototype was subjected to comprehensive testing and evaluation to validate the performance. Using the new repair tool, samples of 4-inch PE pipe with simulated damage were successfully repaired under line pressure to the satisfaction of DOE/NETL and the following natural gas companies: Northwest Natural; Sempra Energy, Southwest Gas Corporation, Questar, and Nicor. However, initial
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NASA Astrophysics Data System (ADS)
Watanabe, Shin; Noda, Isao; Ozaki, Yukihiro
2008-07-01
The amount of nonplanar gauche bonds was monitored as a function of increasing temperature in three different polyethylene (PE) samples by means of mid-infrared (MIR) and near-infrared (NIR) spectroscopy. The hetero-spectral two-dimensional (2D) correlation analysis was carried out between the NIR spectral region of 4365-4235 cm -1 and the well-established MIR spectral region of 1375-1265 cm -1, where bands due to nonplanar conformer are detected. This approach allowed us to identify the NIR band at 4265 cm -1, which behaves in a way similar to MIR bands originating from conformational-defect sequences. By combining the result of our current study and that of our previous report obtained on different types of PE, it is suggested that the NIR band originates from conformational-defect sequences in PE. This finding opens up a unique and useful way to study the state of conformational disorder in PE crystal by NIR spectroscopy, monitoring the intensity of the NIR band at 4265 cm -1. The use of NIR spectroscopy allows researchers to directly probe the degree in the formation of conformational-defect sequences in thick, real-world PE samples that cannot be studied by conventional MIR spectroscopy. The 2D correlation spectroscopy analysis among the MIR CH 2 wagging conformational-defect-mode bands on linear low-density PE (LLDPE) and low-density PE (LDPE) revealed the formation of nonplanar conformer represented by the band at 1368 cm -1 proceeds prior to those by other band at 1308 cm -1. This result agrees well with our previous finding on high-density PE (HDPE). We therefore propose with strong confidence that the bands at 1368 and 1308 cm -1 arise from different conformational-defect sequences, even though both of the bands have been proposed to arise from the same conformer of gtg' ( kink) + gtg sequence.
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An innovative recycling process to obtain pure polyethylene and polypropylene from household waste.
Serranti, Silvia; Luciani, Valentina; Bonifazi, Giuseppe; Hu, Bin; Rem, Peter C
2015-01-01
An innovative recycling process, based on magnetic density separation (MDS) and hyperspectral imaging (HSI), to obtain high quality polypropylene and polyethylene as secondary raw materials, is presented. More in details, MDS was applied to two different polyolefin mixtures coming from household waste. The quality of the two separated PP and PE streams, in terms of purity, was evaluated by a classification procedure based on HSI working in the near infrared range (1000-1700 nm). The classification model was built using known PE and PP samples as training set. The results obtained by HSI were compared with those obtained by classical density analysis carried in laboratory on the same polymers. The results obtained by MDS and the quality assessment of the plastic products by HSI showed that the combined action of these two technologies is a valid solution that can be implemented at industrial level. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Khanoonkon, Nattaporn; Yoksan, Rangrong; Ogale, Amod A
2016-02-10
The present work aims to investigate the effect of stearic acid-grafted starch (ST-SA) on the rheological, thermal, optical, dynamic mechanical thermal, and tensile properties of linear low density polyethylene/thermoplastic starch (LLDPE/TPS) blends, as well as on their water vapor and oxygen barrier properties. Blends consisting of LLDPE and TPS in a weight ratio of 60:40 and ST-SA at different concentrations, i.e. 1, 3 and 5%, were prepared using a twin-screw extruder. The obtained resins were subsequently converted into films via blown film extrusion. Incorporation of ST-SA resulted in a decreased degree of shear thinning, reduced ambient temperature elasticity, and improved tensile strength, secant modulus, extensibility, and UV absorption, as well as diminished water vapor and oxygen permeabilities of the LLDPE/TPS blend. These effects are attributed to the enhanced interfacial adhesion between LLDPE and TPS phases through the compatibilizing effect induced by ST-SA, and the good dispersion of the TPS phase in the LLDPE matrix. The results confirmed that ST-SA could potentially be used as a compatibilizer for the LLDPE/TPS blend system. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Dang, Baokang; Chen, Yipeng; Shen, Xiaoping; Chen, Bo; Sun, Qingfeng; Jin, Chunde
2017-01-01
A polyethylene/wood-fiber composite loaded with nano-ZnO was prepared by a facile hot-press method and was used for the photocatalytic degradation of organic compounds as well as for microwave absorption. ZnO nanoparticles with an average size of 29 nm and polyethylene (PE) powders were dispersed on the wood fibers’ surface through a viscous cationic polyacrylamide (CPAM) solution. The reflection loss (RL) value of the resulting composite was −21 dB, with a thickness of 3.5 mm in the frequency of 17.17 GHz. The PE/ZnO/wood-fiber (PZW) composite exhibited superior photocatalytic activity (84% methyl orange degradation within 300 min) under UV light irradiation. ZnO nanoparticels (NPs) increased the storage modulus of the PZW composite, and the damping factor was transferred to the higher temperature region. The PZW composite exhibited the maximum flexural strength of 58 MPa and a modulus of elasticity (MOE) of 9625 MPa. Meanwhile, it also displayed dimensional stability (thickness swelling value of 9%). PMID:29099777
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NASA Astrophysics Data System (ADS)
McKenzie, Iain; Cortie, David L.; Harada, Masashi; Kiefl, Robert F.; Levy, C. D. Philip; MacFarlane, W. Andrew; McFadden, Ryan M. L.; Morris, Gerald D.; Ogata, Shin-Ichi; Pearson, Matthew R.; Sugiyama, Jun
2017-06-01
β -detected NMR (β -NMR) has been used to study the molecular-scale dynamics of lithium ions in thin films of poly(ethylene oxide) (PEO) containing either lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) or lithium trifluoroacetate (LiTFA) salts at monomer-to-salt ratios (EO/Li) of 8.3. The results are compared with previous β -NMR measurements on pure PEO and PEO with lithium triflate (LiOTf) at the same loading [McKenzie et al., J. Am. Chem. Soc. 136, 7833 (2014)]. Activated hopping of 8Li+ was observed in all of the films above ˜250 K, with the hopping parameters strongly correlated with the ionicity of the lithium salt rather than the polymer glass transition temperature. The pre-exponential factor increases exponentially with ionicity, while the activation energy for hopping increases approximately linearly, going from 6.3 ±0.2 kJ mol-1 in PEO:LiTFA to 17.8 ±0.2 kJ mol-1 in PEO:LiTFSI. The more rapid increase in the pre-exponential factor outweighs the effect of the larger activation energy and results in 8Li+ hopping being fastest in PEO followed by PEO:LiTFSI, PEO:LiOTf, and PEO:LiTFA.
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McKenzie, Iain; Cortie, David L; Harada, Masashi; Kiefl, Robert F; Levy, C D Philip; MacFarlane, W Andrew; McFadden, Ryan M L; Morris, Gerald D; Ogata, Shin-Ichi; Pearson, Matthew R; Sugiyama, Jun
2017-06-28
β-detected NMR (β-NMR) has been used to study the molecular-scale dynamics of lithium ions in thin films of poly(ethylene oxide) (PEO) containing either lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) or lithium trifluoroacetate (LiTFA) salts at monomer-to-salt ratios (EO/Li) of 8.3. The results are compared with previous β-NMR measurements on pure PEO and PEO with lithium triflate (LiOTf) at the same loading [McKenzie et al., J. Am. Chem. Soc. 136, 7833 (2014)]. Activated hopping of 8 Li + was observed in all of the films above ∼250 K, with the hopping parameters strongly correlated with the ionicity of the lithium salt rather than the polymer glass transition temperature. The pre-exponential factor increases exponentially with ionicity, while the activation energy for hopping increases approximately linearly, going from 6.3±0.2 kJ mol -1 in PEO:LiTFA to 17.8±0.2 kJ mol -1 in PEO:LiTFSI. The more rapid increase in the pre-exponential factor outweighs the effect of the larger activation energy and results in 8 Li + hopping being fastest in PEO followed by PEO:LiTFSI, PEO:LiOTf, and PEO:LiTFA.
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Mazurais, D; Ernande, B; Quazuguel, P; Severe, A; Huelvan, C; Madec, L; Mouchel, O; Soudant, P; Robbens, J; Huvet, A; Zambonino-Infante, J
2015-12-01
Microplastics are present in marine habitats worldwide and may be ingested by low trophic organisms such as fish larvae, with uncertain physiological consequences. The present study aims at assessing the impact of polyethylene (PE 10-45 μM) microbeads ingestion in European sea bass (Dicentrarchus labrax) larvae. Fish were fed an inert diet including 0, 10(4) and 10(5) fluorescent microbeads per gram from 7 until 43 days post-hatching (dph). Microbeads were detected in the gastrointestinal tract in all fish fed diet incorporating PE. Our data revealed an efficient elimination of PE beads from the gut since no fluorescent was observed in the larvae after 48 h depuration. While the mortality rate increased significantly with the amount of microbeads scored per larvae at 14 and 20 dph, only ingestion of the highest concentration slightly impacted mortality rates. Larval growth and inflammatory response through Interleukine-1-beta (IL-1β) gene expression were not found to be affected while cytochrome-P450-1A1 (cyp1a1) expression level was significantly positively correlated with the number of microbeads scored per larva at 20 dph. Overall, these results suggest that ingestion of PE microbeads had limited impact on sea bass larvae possibly due to their high potential of egestion. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Study of Polymer Crystallization by Physical Vapor Deposition
NASA Astrophysics Data System (ADS)
Jeong, Hyuncheol
the semi-crystalline structure in MAPLE-deposited polyethylene (PE) films. Depositing PE at various temperatures remarkably allowed for the tunability of the melting temperature and crystallinity of the PE films, thus manipulating the semi-crystalline structure. By comparing the structure of PE formed by different processing routes, i.e., MAPLE and melt-crystallization, we discussed how processing routes affect the development of semi-crystalline phase in polymer films.
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NASA Astrophysics Data System (ADS)
Lee, Hoogil; Jeon, Hyunkyu; Gong, Seokhyeon; Ryou, Myung-Hyun; Lee, Yong Min
2018-01-01
To enhance the uniformity and adhesion properties of water-based ceramic coating layers on hydrophobic polyethylene (PE) separators, their surfaces were treated with thin and hydrophilic polydopamine layers. As a result, an aqueous ceramic coating slurry consisting of Al2O3 particles, carboxyl methyl cellulose (CMC) binders, and water solvent was easily spread on the separator surface, and a uniform ceramic layer was formed after solvent drying. Moreover, the ceramic coating layer showed greatly improved adhesion properties to the PE separator surface. Whereas the adhesion strength within the bulk coating layer (Fmid) ranged from 43 to 86 N m-1 depending on the binder content of 1.5-3.0 wt%, the adhesion strength at the interface between the ceramic coating layer and PE separator (Fsepa-Al2O3) was 245-360 N m-1, a value equivalent to an increase of four or five times. Furthermore, an additional ceramic coating layer of approximately 7 μm did not degrade the ionic conductivity and electrochemical properties of the bare PE separators. Thus, all the LiMn2O4/graphite cells with ceramic-coated separators delivered an improved cycle life and rate capability compared with those of the control cells with bare PE separators.
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Li, Yan; Liu, Hongyi; Song, Junlong; Rojas, Orlando J; Hinestroza, Juan P
2011-07-01
The association of a symmetric polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO(19)-PPO(29)-PEO(19)) triblock copolymer adsorbed from aqueous solutions onto polypropylene (PP), polyethylene (PE), and cellulose surfaces was probed using Atomic Force Microscopy (AFM). Significant morphological differences between the polyolefin substrates (PP and PE) and the cellulose surfaces were observed after immersion of the films in the PEO(19)-PPO(29)-PEO(19) solutions. When the samples were scanned, while immersed in solutions of the triblock copolymer, it was revealed that the structures adsorbed on the polyolefin surfaces were smoothed by the adsorbed PEO(19)-PPO(29)-PEO(19). In contrast, those structures on the hydrophilic cellulose surfaces were sharpened. These observations were related to the roughness of the substrate and the energy of interaction between the surfaces and the PEO and PPO polymer segments. The interaction energy between each of the blocks and the surface was calculated using molecular dynamics simulations. It is speculated that the associative structures amply reported in aqueous solution at concentrations above the critical micelle concentration, CMC, are not necessarily preserved upon adsorption; instead, it appears that molecular arrangements of the anchor-buoy type and hemimicelles prevail. The reported data suggests that the roughness of the surface, as well as its degree of hydrophobicity, have a large influence on the nature of the resulting adsorbed layer. The reported observations are valuable in explaining the behavior of finishing additives and lubricants commonly used in textile and fiber processing, as well as the effect of the morphology of the boundary layers on friction and wear, especially in the case of symmetric triblock copolymers, which are commonly used as antifriction, antiwear additives.
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Polyethylene recycling: Waste policy scenario analysis for the EU-27.
Andreoni, Valeria; Saveyn, Hans G M; Eder, Peter
2015-08-01
This paper quantifies the main impacts that the adoption of the best recycling practices together with a reduction in the consumption of single-use plastic bags and the adoption of a kerbside collection system could have on the 27 Member States of the EU. The main consequences in terms of employment, waste management costs, emissions and energy use have been quantified for two scenarios of polyethylene (PE) waste production and recycling. That is to say, a "business as usual scenario", where the 2012 performances of PE waste production and recycling are extrapolated to 2020, is compared to a "best practice scenario", where the best available recycling practices are modelled together with the possible adoption of the amended Packaging and Packaging Waste Directive related to the consumption of single-use plastic bags and the implementation of a kerbside collection system. The main results show that socio-economic and environmental benefits can be generated across the EU by the implementation of the best practice scenario. In particular, estimations show a possible reduction of 4.4 million tonnes of non-recycled PE waste, together with a reduction of around €90 million in waste management costs in 2020 for the best practice scenario versus the business as usual scenario. An additional 35,622 jobs are also expected to be created. In environmental terms, the quantity of CO2 equivalent emissions could be reduced by around 1.46 million tonnes and the net energy requirements are expected to increase by 16.5 million GJ as a consequence of the reduction in the energy produced from waste. The main analysis provided in this paper, together with the data and the model presented, can be useful to identify the possible costs and benefits that the implementation of PE waste policies and Directives could generate for the EU. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Determinants of PE Teachers Career Intentions
ERIC Educational Resources Information Center
Mäkelä, Kasper; Hirvensalo, Mirja; Whipp, Peter R.
2015-01-01
One of the cause's célèbre in the field of education has been teacher attrition; Physical education (PE) is no different. Some PE teachers are leaving the profession because they encounter stress and dissatisfaction in their profession. The purpose of this study is to determine the aspects that keep PE teachers happy and remaining in the…
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ERIC Educational Resources Information Center
Morgan, Philip; Bourke, Sid
2008-01-01
Background: Over the past 20 years, a number of researchers have expressed concern over the lack of confidence and qualifications of primary school teachers to teach PE. Evidently, the influence of personal school PE experiences may play an important role in the development of teachers' confidence to appropriately teach PE. Most research that has…
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A review of nondestructive examination technology for polyethylene pipe in nuclear power plant
NASA Astrophysics Data System (ADS)
Zheng, Jinyang; Zhang, Yue; Hou, Dongsheng; Qin, Yinkang; Guo, Weican; Zhang, Chuck; Shi, Jianfeng
2018-05-01
Polyethylene (PE) pipe, particularly high-density polyethylene (HDPE) pipe, has been successfully utilized to transport cooling water for both non-safety- and safety-related applications in nuclear power plant (NPP). Though ASME Code Case N755, which is the first code case related to NPP HDPE pipe, requires a thorough nondestructive examination (NDE) of HDPE joints. However, no executable regulations presently exist because of the lack of a feasible NDE technique for HDPE pipe in NPP. This work presents a review of current developments in NDE technology for both HDPE pipe in NPP with a diameter of less than 400 mm and that of a larger size. For the former category, phased array ultrasonic technique is proven effective for inspecting typical defects in HDPE pipe, and is thus used in Chinese national standards GB/T 29460 and GB/T 29461. A defect-recognition technique is developed based on pattern recognition, and a safety assessment principle is summarized from the database of destructive testing. On the other hand, recent research and practical studies reveal that in current ultrasonic-inspection technology, the absence of effective ultrasonic inspection for large size was lack of consideration of the viscoelasticity effect of PE on acoustic wave propagation in current ultrasonic inspection technology. Furthermore, main technical problems were analyzed in the paper to achieve an effective ultrasonic test method in accordance to the safety and efficiency requirements of related regulations and standards. Finally, the development trend and challenges of NDE test technology for HDPE in NPP are discussed.
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Busse, B; Niecke, M; Püschel, K; Delling, G; Katzer, A; Hahn, M
2007-01-01
Periprosthetic tissue was analysed by the combination of different investigation techniques without destruction. The localisation and geometry of polyethylene abrasion particles were determined quantitatively to differentiate between abrasion due to function and abrasion due to implant loosening. Non-polyethylene particles from implant components which contaminate the tissue were micro-analytically measured. The results will help us to understand loosening mechanisms and thus lead to implant optimisations. A non-destructive particle analysis using highly sensitive proton-induced X-ray emission (PIXE) was developed to achieve a better histological allocation. Five autopsy cases with firmly fitting hip endoprosthesis (2 x Endo-Modell Mark III, 1 x St. Georg Mark II, LINK, Germany; 2 x Spongiosa Metal II, ESKA, Germany) were prepared as ground tissue specimens. Wear investigations were accomplished with a combined application of different microscopic techniques and microanalysis. The abrasion due to implant loosening was histologically evaluated on 293 loosened cup implants (St. Georg Mark II, LINK, Germany). Wear particles are heterogeneously distributed in the soft tissue. In cases of cemented prostheses, cement particles are dominating whereas metal particles could rarely be detected. The concentration of the alloy constituent cobalt (Co) is increased in the mineralised bone tissue. The measured co-depositions depend on the localisation and/or lifetime of an implant. Functional polyethylene (PE) abrasion needs to be differentiated from PE abrasion of another genesis (loosening, impingement) morphologically and by different tissue reactions. In the past a reduction of abrasion was targeted primarily by the optimisation of the bearing surfaces and tribology. The interpretation of our findings indicates that different mechanisms of origin in terms of tissue contamination with wear debris and the alloy should be included in the improvement of implants or implantation
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NASA Astrophysics Data System (ADS)
Kim, Doyoung; Kang, Hyemin; Kim, Jae-Min; Kim, Hyungjun
2011-02-01
Zinc oxide (ZnO) thin films were prepared by plasma-enhanced atomic layer deposition (PE-ALD) using oxygen plasma as a reactant and the properties were compared with those of thermal atomic layer deposition (TH-ALD) ZnO thin films. While hexagonal wurzite phase with preferential (0 0 2) orientation was obtained for both cases, significant differences were observed in various aspects of film properties including resistivity values between these two techniques. Photoluminescence (PL) measurements have shown that high resistivity of PE-ALD ZnO thin films is due to the oxygen interstitials at low growth temperature of 200 °C, whose amount decreases with increasing growth temperature. Thin film transistors (TFT) using TH- and PE-ALD ZnO as an active layer were also fabricated and the device properties were evaluated comparatively.
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Esmaeili, Atefeh; Pourbabaee, Ahmad Ali; Alikhani, Hossein Ali; Shabani, Farzin; Esmaeili, Ensieh
2013-01-01
In this study, two strains of Aspergillus sp. and Lysinibacillus sp. with remarkable abilities to degrade low-density polyethylene (LDPE) were isolated from landfill soils in Tehran using enrichment culture and screening procedures. The biodegradation process was performed for 126 days in soil using UV- and non-UV-irradiated pure LDPE films without pro-oxidant additives in the presence and absence of mixed cultures of selected microorganisms. The process was monitored by measuring the microbial population, the biomass carbon, pH and respiration in the soil, and the mechanical properties of the films. The carbon dioxide measurements in the soil showed that the biodegradation in the un-inoculated treatments were slow and were about 7.6% and 8.6% of the mineralisation measured for the non-UV-irradiated and UV-irradiated LDPE, respectively, after 126 days. In contrast, in the presence of the selected microorganisms, biodegradation was much more efficient and the percentages of biodegradation were 29.5% and 15.8% for the UV-irradiated and non-UV-irradiated films, respectively. The percentage decrease in the carbonyl index was higher for the UV-irradiated LDPE when the biodegradation was performed in soil inoculated with the selected microorganisms. The percentage elongation of the films decreased during the biodegradation process. The Fourier transform infra-red (FT-IR), x-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to determine structural, morphological and surface changes on polyethylene. These analyses showed that the selected microorganisms could modify and colonise both types of polyethylene. This study also confirmed the ability of these isolates to utilise virgin polyethylene without pro-oxidant additives and oxidation pretreatment, as the carbon source. PMID:24086254
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Esmaeili, Atefeh; Pourbabaee, Ahmad Ali; Alikhani, Hossein Ali; Shabani, Farzin; Esmaeili, Ensieh
2013-01-01
In this study, two strains of Aspergillus sp. and Lysinibacillus sp. with remarkable abilities to degrade low-density polyethylene (LDPE) were isolated from landfill soils in Tehran using enrichment culture and screening procedures. The biodegradation process was performed for 126 days in soil using UV- and non-UV-irradiated pure LDPE films without pro-oxidant additives in the presence and absence of mixed cultures of selected microorganisms. The process was monitored by measuring the microbial population, the biomass carbon, pH and respiration in the soil, and the mechanical properties of the films. The carbon dioxide measurements in the soil showed that the biodegradation in the un-inoculated treatments were slow and were about 7.6% and 8.6% of the mineralisation measured for the non-UV-irradiated and UV-irradiated LDPE, respectively, after 126 days. In contrast, in the presence of the selected microorganisms, biodegradation was much more efficient and the percentages of biodegradation were 29.5% and 15.8% for the UV-irradiated and non-UV-irradiated films, respectively. The percentage decrease in the carbonyl index was higher for the UV-irradiated LDPE when the biodegradation was performed in soil inoculated with the selected microorganisms. The percentage elongation of the films decreased during the biodegradation process. The Fourier transform infra-red (FT-IR), x-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to determine structural, morphological and surface changes on polyethylene. These analyses showed that the selected microorganisms could modify and colonise both types of polyethylene. This study also confirmed the ability of these isolates to utilise virgin polyethylene without pro-oxidant additives and oxidation pretreatment, as the carbon source.
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Fast Postmoisture Treatment of Luminescent Perovskite Films for Efficient Light-Emitting Diodes.
Wang, Haoran; Li, Xiaomin; Yuan, Mingjian; Yang, Xuyong
2018-04-01
Despite the recent advances in the performance of perovskite light-emitting diodes (PeLEDs), the effects of water on the perovskite emissive layer and its electroluminescence are still unclear, even though it has been previously demonstrated that moisture has a significant impact on the quality of perovskite films in the fabrication process of perovskite solar cells and is a prerequisite for obtaining high-performance PeLEDs. Here, the effects of postmoisture on the luminescent CH 3 NH 3 PbBr 3 (MAPbBr 3 ) perovskite films are systematically investigated. It is found that postmoisture treatment can efficiently control the morphology and growth of perovskite films and only a fast moisture exposure at a 60% high relative humidity results in significantly improved crystallinity, carrier lifetime, and photoluminescence quantum yield of perovskite films. With the optimized moisture-treated perovskite films, a high-performance PeLED is fabricated, exhibiting a maximum current efficiency of 20.4 cd A -1 , which is an almost 20-fold enhancement when compared with perovskite films without moisture treatment. The results provide valuable insights into the moisture-assisted growth of luminescent perovskite films and will aid in the development of high-performance perovskite light-emitting devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Paseiro-Cerrato, Rafael; Rodríguez-Bernaldo de Quirós, Ana; Otero-Pazos, Pablo; Sendón, Raquel; Paseiro-Losada, Perfecto
2018-03-01
The aim of the present study was to determine the migration kinetics of one photoinitiator, benzophenone, and two optical brighteners, Uvitex OB and 1,4-diphenyl-1,3-butadiene (DPBD), from low-density polyethylene (LDPE) films into cake. Transfer was assessed by both direct contact and also the vapour phase. To perform the migration tests by direct contact, plastic films enriched with the additives were placed between two cake slices. To evaluate the migration through the gas phase, cake and the fortified LDPE film were placed with no direct contact in a glass container that was hermetically closed. Samples were stored at different time-temperature conditions. Target compounds were extracted from the films with ethanol (70°C, 24 h) and analysed by HPLC-DAD. Relevant parameters such as partition and diffusion coefficients between food and plastic film were calculated. The Arrhenius equation was applied to estimate the diffusion coefficient at any temperature. The data indicate that migration of benzophenone occurs in a significant extent into cake by both direct contact and through the gas phase (no direct contact). Conversely, very little migration occurred for Uvitex OB by direct contact and none through the gas phase. Results for benzophenone suggest that migration through the gas phase should be considered when evaluating migration from food packaging materials into food.
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Morphologies of precise polyethylene-based acid copolymers and ionomers
NASA Astrophysics Data System (ADS)
Buitrago, C. Francisco
Acid copolymers and ionomers are polymers that contain a small fraction of covalently bound acidic or ionic groups, respectively. For the specific case of polyethylene (PE), acid and ionic pendants enhance many of the physical properties such as toughness, adhesion and rheological properties. These improved properties result from microphase separated aggregates of the polar pendants in the non-polar PE matrix. Despite the widespread industrial use of these materials, rigorous chemical structure---morphology---property relationships remain elusive due to the inevitable structural heterogeneities in the historically-available acid copolymers and ionomers. Recently, precise acid copolymers and ionomers were successfully synthesized by acyclic diene metathesis (ADMET) polymerization. These precise materials are linear, high molecular weight PEs with pendant acid or ionic functional groups separated by a precisely controlled number of carbon atoms. The morphologies of nine precise acid copolymers and eleven precise ionomers were investigated by X-ray scattering, solid-state 13C nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). For comparison, the morphologies of linear PEs with pseudo-random placement of the pendant groups were also studied. Previous studies of precise copolymers with acrylic acid (AA) found that the microstructural precision produces a new morphology in which PE crystals drive the acid aggregates into layers perpendicular to the chain axes and presumably at the interface between crystalline and amorphous phases. In this dissertation, a second new morphology for acid copolymers is identified in which the aggregates arrange on cubic lattices. The fist report of a cubic morphology was observed at room and elevated temperatures for a copolymer functionalized with two phosphonic acid (PA) groups on every 21st carbon atom. The cubic lattice has been identified as face-centered cubic (FCC). Overall, three morphology types have been
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Tomsej, Tomas; Horak, Jiri; Tomsejova, Sarka; Krpec, Kamil; Klanova, Jana; Dej, Milan; Hopan, Frantisek
2018-04-01
The aim of this study was to simulate a banned but widely spread practice of co-combustion of plastic with wood in a small residential boiler and to quantify its impact on emissions of gaseous pollutants, particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and 1,3,5-triphenylbenzene (135TPB), a new tracer of polyethylene plastic combustion. Supermarket polyethylene shopping bags (PE) and polyethylene terephthalate bottles (PET) were burnt as supplementary fuels with beech logs (BL) in an old-type 20 kW over-fire boiler both at a nominal and reduced heat output. An impact of co-combustion was more pronounced at the nominal heat output: an increase in emissions of PM, total organic carbon (TOC), toxic equivalent (TEQ) of 7 carcinogenic PAHs (c-PAHs) and a higher ratio of c-PAHs TEQ in particulate phase was observed during co-combustion of both plastics. 135TPB was found in emissions from both plastics both at a nominal and reduced output. In contrast to findings reported in the literature, 135TPB was a dominant compound detected by mass spectrometry on m/z 306 exclusively in emissions from co-combustion of PE. Surprisingly, six other even more abundant compounds of unknown identity were found on this m/z in emissions from co-combustion of PET. One of these unknown compounds was identified as p-quaterphenyl (pQ). Principal component analysis revealed strong correlation among 135TPB, pQ and five unknown compounds. pQ seems to be suitable tracers of polyethylene terephthalate plastic co-combustion, while 135TPB proved its suitability to be an all-purpose tracer of polyethylene plastics combustion. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Sosna, A; Radonský, T; Pokorný, D; Veigl, D; Horák, Z; Jahoda, D
2003-01-01
The experience obtained during revision surgery and findings of polyethylene granulomas in surrounding tissues of replacement as well as marked differences in the viability of implants resulted in the study of polyethylene disease and its basic mechanisms producing the development of osteoaggressive granulomas. We investigated the morphology of particles and their number in tissues surrounding the implant. The aim of our study was to develop a method for the detection of polyethylene particles in tissues, to identify different types of wear and to assess factors that may influence the viability of joint arthroplasty in general. Every revizion of joint arthroplasty performed during the last five years was evaluated in terms of the presence of polyethylene granules and the viability state of articular polyethylene inserts. A total of 55 samples were taken from tissues around loosened endoprostheses. The location of each sample was exactly determined. A technique was developed to identify wear particles and to visualize them after all organic structures of a polyethylene granuloma were dissolved with nitrogenic acid. The viability of articular polyethylene implants showed extreme differences in relation to different periods of manufacture and probably also to different methods of sterilization. Articular inserts sterilized with formaldehyde (the method used at the beginning of arthroplasty in our country) showed the highest viability and the lowest wear. The polyethylene particles present in tissues surrounding the implant were characterized in terms of morphology and size. The comparison of literature data and our results has revealed that there are many unknown facts about the quality and structure of polyethylene. The method of sterilization also appears to play a role. Because the issue is complex, we were not able to identify all factors leading, in some cases, to an early and unexpected failure of the implant and we consider further investigation to be necessary
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Dynamics in entangled polyethylene melts using coarse-grained models
NASA Astrophysics Data System (ADS)
Peters, Brandon L.; Grest, Gary S.; Salerno, K. Michael; Agrawal, Anupriya; Perahia, Dvora
Polymer dynamics creates distinctive viscoelastic behavior as a result of a coupled interplay of motion on multiple length scales. Capturing the broad time and length scales of polymeric motion however, remains a challenge. Using polyethylene (PE) as a model system, we probe the effects of the degree of coarse graining on polymer dynamics. Coarse-grained (CG) potentials are derived using iterative Boltzmann inversion (iBi) with 2-6 methyl groups per CG bead from all fully atomistic melt simulations for short chains. While the iBi methods produces non-bonded potentials which give excellent agreement for the atomistic and CG pair correlation functions, the pressure P = 100-500MPa for the CG model. Correcting for potential so P 0 leads to non-bonded models with slightly smaller effective diameter and much deeper minimum. However, both the pressure and non-pressure corrected CG models give similar results for mean squared displacement (MSD) and the stress auto correlation function G(t) for PE melts above the melting point. The time rescaling factor between CG and atomistic models is found to be nearly the same for both CG models. Transferability of potential for different temperatures was tested by comparing the MSD and G(t) for potentials generated at different temperatures.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Rao, T. Rajavardhana; Raju, Ch. Linga, E-mail: drchlraj-phy@yahoo.com; Brahmam, K. Veera
2015-05-15
Polymer films of Poly(vinylalcohol) (PVA) complexed with Polyethylene glycol (PEG) with different dopant concentrations of Cr{sup 3+} ions are prepared by solution cast technique. Electron paramagnetic resonance (EPR), Optical absorption and FT-IR studies have been carried out on the polymer films. The EPR spectra of the entire samples exhibit resonance signal at g ≈1.97 which is attributed to the isolated Cr{sup 3+} pairs. The temperature variation EPR studies show that the population of spin-levels participating in the resonance decreases with an increase in temperature, which is in accordance with the Boltzmann Law. The paramagnetic susceptibilities (X) have been calculated frommore » the EPR data at different temperatures. The linewidth of the g ≈1.97 resonance signal has been found to be decreasing with an increase in temperature, which confirms the pairing mechanism between Cr{sup 3+} ions. The Optical absorption spectrum of chromium ions in (PVA+PEG) polymer films exhibits three bands, corresponding to the d-d transitions {sup 4}A{sub 2g}(F)→{sup 4}T{sub 1g}(F), {sup 4}A{sub 2g}(F)→{sup 4}T{sub 2g}(F) and {sup 4}A{sub 2g}(F)→{sup 2}T{sub 1g}(G), in the order of decreasing energy. The crystal field parameter Dq and the Racah interelectronic repulsion parameters B and C have been evaluated. From the ultraviolet absorption edges, Optical band gap (E{sub opt}) and Urbach (ΔE) energies are evaluated. FT-IR spectrum exhibits few bands which are attributed to O-H, CH, C=C and C=O groups of stretching and bending vibrations.« less
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Liu, H; Wu, Q; Zhang, Q
2009-12-01
Banana fiber (BaF)-filled composites based on high density polyethylene (HDPE)/Nylon-6 blends were prepared via a two-step extrusion method. Maleic anhydride grafted styrene/ethylene-butylene/styrene triblock polymer (SEBS-g-MA) and maleic anhydride grafted polyethylene (PE-g-MA) were used to enhance impact performance and interfacial bonding between BaF and the resins. Mechanical, crystallization/melting, thermal stability, water absorption, and morphological properties of the composites were investigated. In the presence of SEBS-g-MA, better strengths and moduli were found for HDPE/Nylon-6 based composites compared with corresponding HDPE based composites. At a fixed weight ratio of PE-g-MA to BaF, an increase of BaF loading up to 48.2 wt.% led to a continuous improvement in moduli and flexural strength of final composites, while impact toughness was lowered gradually. Predicted tensile modulus by the Hones-Paul model for three-dimensional random fiber orientation agreed well with experimental data at the BaF loading of 29.3 wt.%. However, the randomly-oriented fiber models underestimated experimental data at higher fiber levels. It was found that the presence of SEBS-g-MA had a positive influence on reinforcing effect of the Nylon-6 component in the composites. Thermal analysis results showed that fractionated crystallization of the Nylon-6 component in the composites was induced by the addition of both SEBS-g-MA and PE-g-MA. Thermal stability of both composite systems differed slightly, except an additional decomposition peak related to the minor Nylon-6 for the composites from the HDPE/Nylon-6 blends. In the presence of SEBS-g-MA, the addition of Nylon-6 and increased BaF loading level led to an increase in the water absorption value of the composites.
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JROTC as a Substitute for PE: Really?
Lounsbery, Monica A. F.; Holt, Kathryn A.; Monnat, Shannon A.; McKenzie, Thomas L.; Funk, Brian
2014-01-01
Purpose Even though physical education (PE) is an evidence-based strategy for providing and promoting physical activity, alternative programs such as Junior Reserve Officer Training Corps (JROTC) are commonly substituted for PE in many states. The purpose of this study was to compare student physical activity and lesson contexts during high school PE and JROTC sessions. Method SOFIT (System for Observing Fitness Instruction Time) was used to assess PE and JROTC sessions (N=38 each) in 4 high schools that provided both programs. Data were analyzed using t-tests, negative binomial regression, and logistic regression. Results Students engaged in significantly more moderate to vigorous physical activity during PE than JROTC sessions and they were significantly less sedentary. Significant differences between the two program types were also found among lesson contexts. Conclusions PE and JROTC provide substantially different content and contexts and students in them engage in substantially different amounts of moderate to vigorous physical activity. Students in JROTC, and perhaps other alternative programs, are less likely to accrue health-supporting physical activity and engage in fewer opportunities to be physically fit and motorically skilled. Policies and practices for providing substitutions for PE should be carefully examined. PMID:25141093
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Ammonia gas permeability of meat packaging materials.
Karim, Faris; Hijaz, Faraj; Kastner, Curtis L; Smith, J Scott
2011-03-01
Meat products are packaged in polymer films designed to protect the product from exterior contaminants such as light, humidity, and harmful chemicals. Unfortunately, there is almost no data on ammonia permeability of packaging films. We investigated ammonia permeability of common meat packaging films: low-density polyethylene (LDPE; 2.2 mil), multilayer polyolefin (MLP; 3 mil), and vacuum (V-PA/PE; 3 mil, 0.6 mil polyamide/2.4 mil polyethylene). The films were fabricated into 10 × 5 cm pouches and filled with 50 mL deionized water. Pouches were placed in a plexiglass enclosure in a freezer and exposed to 50, 100, 250, or 500 ppm ammonia gas for 6, 12, 24, and 48 h at -17 ± 3 °C and 21 ± 3 °C. At freezing temperatures, no ammonia residues were detected and no differences in pH were found in the water. At room temperature, ammonia levels and pH of the water increased significantly (P < 0.05) with increasing exposure times and ammonia concentrations. Average ammonia levels in the water were 7.77 ppm for MLP, 5.94 ppm for LDPE, and 0.89 ppm for V-PA/PE at 500 ppm exposure for 48 h at 21 ± 3 °C. Average pH values were 8.64 for MLP, 8.38 for LDPE, and 7.23 for V-PA/PE (unexposed ranged from 5.49 to 6.44) at 500 ppm exposure for 48 h. The results showed that temperature influenced ammonia permeability. Meat packaging materials have low ammonia permeability and protect meat products exposed to ammonia leaks during frozen storage.
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Buccino, Carla; Ferrara, Carmen; Malvano, Carmela; De Feo, Giovanni
2017-11-07
This study presents an evaluation of the environmental performance of an ice cream cup made of polyethylene (PE)/paper laminate using a life cycle assessment approach 'from cradle to grave'. Two opposite alternative disposal scenarios, as well as their intermediate combinations, were considered: 100% incineration and 100% landfilling. The environmental impacts were calculated using the EPD 2013 evaluation method since the study was developed in an Environmental Product Declaration perspective as well as the method ReCiPe 2008 H at the endpoint level. PE/paper laminate production was the most impactful process since it provided the highest contribution to total impacts in four of six impact categories considered. Ice cream cup production was the second impactful process. The 100% incineration scenario provided negligible contribution to life cycle total impact for all impact categories; while considering the landfilling scenario, the percentage contributions to the total impact provided by the end-of-life phase increased considerably, until to be comparable to the contributions provided by the production processes of the PE/paper laminate and the ice cream cup. The obtained results highlighted that different disposal scenarios can affect significantly the conclusions of a study. At the endpoint level, incineration was more environmentally sound than landfilling for all the ReCiPe damage categories.
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Effect of Aspergillus versicolor strain JASS1 on low density polyethylene degradation
NASA Astrophysics Data System (ADS)
Gajendiran, A.; Subramani, S.; Abraham, J.
2017-11-01
Low density polyethylene (LDPE) waste disposal remains one of the major environmental concerns faced by the world today. In past decades, major focus has been given to enhance the biodegradation of LDPE by microbial species. In this present study, Aspergillus versicolor with the ability to degrade LDPE was isolated from municipal landfill area using enrichment technique. Based on 18S rRNA gene sequencing confirmed its identity as Aspergillus versicolor. The biodegradation study was carried out for 90 d in M1 medium. The degradation behaviour of LDPE films by Aspergillus versicolor strain JASS1 were confirmed by weight loss, CO2 evolution, Scanning electron microscopy (SEM) analysis, Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) technique. From current investigation, it can be concluded that our isolated strain JASS1 had the potential to degrade LDPE films and it can be useful in solving the problem caused by polyethylene in the environment.
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NASA Astrophysics Data System (ADS)
Tang, Hao; Hu, Fuxiang; Xu, Liuxiong; Dong, Shuchuang; Zhou, Cheng; Wang, Xuefang
2017-10-01
Knotless polyethylene (PE) netting has been widely used in aquaculture cages and fishing gears, especially in Japan. In this study, the hydrodynamic coefficient of six knotless PE netting panels with different solidity ratios were assessed in a flume tank under various attack angles of netting from 0° (parallel to flow) to 90° (perpendicular to flow) and current speeds from 40 cm s-1 to 130 cm s-1. It was found that the drag coefficient was related to Reynolds number, solidity ratio and attack angle of netting. The solidity ratio was positively related with drag coefficient for netting panel perpendicular to flow, whereas when setting the netting panel parallel to the flow the opposite result was obtained. For netting panels placed at an angle to the flow, the lift coefficient reached the maximum at an attack angle of 50° and then decreased as the attack angle further increased. The solidity ratio had a dual influence on drag coefficient of inclined netting panels. Compared to result in the literature, the normal drag coefficient of knotless PE netting measured in this study is larger than that of nylon netting or Dyneema netting.
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ERIC Educational Resources Information Center
Stover, Del
2005-01-01
Because some students need to drop some extracurricular activities in order to enroll in a PE class, public schools have developed PE courses that can be fitted into students' tight schedules. These programs are popular because of convenience. Not only can workouts be scheduled as desired, but students can sweat it out almost anywhere: the local…
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Song, Ah Young; Choi, Ha Young; Lee, Eun Song; Han, Jaejoon; Min, Sea C
2018-04-01
Films containing microencapsulated cinnamon oil (CO) were developed using a large-scale production system to protect against the Indian meal moth (Plodia interpunctella). CO at concentrations of 0%, 0.8%, or 1.7% (w/w ink mixture) was microencapsulated with polyvinyl alcohol. The microencapsulated CO emulsion was mixed with ink (47% or 59%, w/w) and thinner (20% or 25%, w/w) and coated on polypropylene (PP) films. The PP film was then laminated with a low-density polyethylene (LDPE) film on the coated side. The film with microencapsulated CO at 1.7% repelled P. interpunctella most effectively. Microencapsulation did not negatively affect insect repelling activity. The release rate of cinnamaldehyde, an active repellent, was lower when CO was microencapsulated than that in the absence of microencapsulation. Thermogravimetric analysis exhibited that microencapsulation prevented the volatilization of CO. The tensile strength, percentage elongation at break, elastic modulus, and water vapor permeability of the films indicated that microencapsulation did not affect the tensile and moisture barrier properties (P > 0.05). The results of this study suggest that effective films for the prevention of Indian meal moth invasion can be produced by the microencapsulation of CO using a large-scale film production system. Low-density polyethylene-laminated polypropylene films printed with ink incorporating microencapsulated cinnamon oil using a large-scale film production system effectively repelled Indian meal moth larvae. Without altering the tensile and moisture barrier properties of the film, microencapsulation resulted in the release of an active repellent for extended periods with a high thermal stability of cinnamon oil, enabling commercial film production at high temperatures. This anti-insect film system may have applications to other food-packaging films that use the same ink-printing platform. © 2018 Institute of Food Technologists®.
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NASA Astrophysics Data System (ADS)
Hussein, M.
2018-06-01
The influence of the mechanical property and morphology of different blend ratio of Butyl rubber (IIR)/high molecular weight polyethylene (PE) by temperature and strain rate are performed. Special attention has been considered to a ductile-brittle transition that is known to occur at around 60 °C. The idea is to explain the unexpected phenomenon of brittleness which directly related to all tensile mechanical properties such as the strength of blends, modulus of elasticity of filled and unfilled IIR-polyethylene blends. In particular, the initial Young's modulus, tensile strength and strain at failure exhibit similar dependency on strain rate and temperature. These quantities lowered and increased with an increment of temperature, whereas the increased with increasing of strain rate. Furthermore, the tensile strength and strain at failure decreases for all temperatures range with the increase of PE content in the blend, except Young's modulus in reverse. The strain rate sensitivity index parameter of the examined polymeric materials is consistent with the micro-mechanisms of deformation and the behavior was well described by an Eyring relationship leading to an activation volume of ∼1 nm3, except for the highest value of unfilled IIR ∼8.45 nm3.
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Kakuda, Hiroyuki; Okada, Tetsuo; Otsuka, Makoto; Katsumoto, Yukiteru; Hasegawa, Takeshi
2009-01-01
A multivariate analytical technique has been applied to the analysis of simultaneous measurement data from differential scanning calorimetry (DSC) and X-ray diffraction (XRD) in order to study thermal changes in crystalline structure of a linear poly(ethylene imine) (LPEI) film. A large number of XRD patterns generated from the simultaneous measurements were subjected to an augmented alternative least-squares (ALS) regression analysis, and the XRD patterns were readily decomposed into chemically independent XRD patterns and their thermal profiles were also obtained at the same time. The decomposed XRD patterns and the profiles were useful in discussing the minute peaks in the DSC. The analytical results revealed the following changes of polymorphisms in detail: An LPEI film prepared by casting an aqueous solution was composed of sesquihydrate and hemihydrate crystals. The sesquihydrate one was lost at an early stage of heating, and the film changed into an amorphous state. Once the sesquihydrate was lost by heating, it was not recovered even when it was cooled back to room temperature. When the sample was heated again, structural changes were found between the hemihydrate and the amorphous components. In this manner, the simultaneous DSC-XRD measurements combined with ALS analysis proved to be powerful for obtaining a better understanding of the thermally induced changes of the crystalline structure in a polymer film.
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NASA Astrophysics Data System (ADS)
Irena, Gancarz; Jolanta, Bryjak; Karolina, Zynek
2009-07-01
Poly(ethylene terephthalate) (PET) film was modified by reaction with hydrazine (HD), ethylenediamine (EDA), 1,2-diaminopropane (1,2-DAP) and 1,3-diaminopropane (1,3-DAP). The maximal amount of amine functionalities introduced in the chosen conditions on the surface was found as 0.07, 3.35, 0.76 and 1.99 nmol cm -2 for HD, EDA, 1,2-DAP and 1,3-DAP respectively. During the modification process etching of the sample and an increase of stiffness takes place. FTIR-ATR spectra prove that the surface chemistry after modification in amine solution is very complex. The lack of clear correlation between the surface tension and surface concentration of amine functionalities seems to confirm that. For immobilization purpose invertase, laccase and tyrosinase were used. The amount of covalently attached proteins at first increases with the increase of surface concentration of amine groups but after reaching a certain level of amine groups, decrease of the immobilization level was observed. All enzymes tested showed highest activity for a moderate level of aminolysis and this activity had the highest values for EDA-modified PET.
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NASA Astrophysics Data System (ADS)
Ji, Jianying
Solid polymer electrolytes (SPEs) provide advantages over liquid electrolytes in terms of safety, reliability, less temperature sensitive, and simplicity of design. With the use of a SPE in lithium batteries, high specific energy and specific power, safe operation, flexibility in packaging, and low cost of fabrication can be expected. However, after 30 years, SPEs have rarely found commercial success due to the low ionic conductivity and/or insufficient mechanical properties, both of which are related to the movement of the polymer chains. Many physical/chemical methods have been exploited to simultaneously create enhancement in ionic conductivity and mechanical properties, and some suggested ways have shown promise. However, the complex strategies have always introduced other challenge issues and incurred extra costs for manufacturing. In such a context, the development of dry solid state electrolytes is the central challenge to be faced worldwide. This thesis deals with the approaches to improving ionic conductivity and mechanical properties simultaneously. The method is to apply two kinds of controllable organic fillers: copolymer and protein. Our work revealed that the commercial available copolymer, poly (ethylene oxide)- block-polyethylene (PEO-b-PE), possesses a capability for enhancing the multiple performances of poly(ethylene oxide)(PEO)-based polymer electrolyte. And the effects of composition and molecular weight of the copolymers on performance of the resulting SPEs were examined. It was found that increasing the PE block percentage in the copolymer resulted in a significant increase in both ionic conductivity and mechanical properties, while increasing the molecular weight of the copolymer resulted in better mechanical properties, and an identical ionic conductivity. A rubber-like, soy protein-based SPE (s-SPE)was obtained by employing soy protein isolate (SPI), a soy product usually used as rigid fillers for enhancing mechanical properties of
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Combating oil spill problem using plastic waste.
Saleem, Junaid; Ning, Chao; Barford, John; McKay, Gordon
2015-10-01
Thermoplastic polymers (such as polypropylene, polyethylene, polyethylene terephthalate (PET) and high density polyethylene (HDPE)) constitute 5-15% of municipal solid waste produced across the world. A huge quantity of plastic waste is disposed of each year and is mostly either discarded in landfills or incinerated. On the other hand, the usage of synthetic polymers as oil sorbents, in particular, polyolefins, including polypropylene (PP), and polyethylene (PE) are the most commonly used oil sorbent materials mainly due to their low cost. However, they possess relatively low oil absorption capacities. In this work, we provide an innovative way to produce a value-added product such as oil-sorbent film with high practical oil uptake values in terms of g/g from waste HDPE bottles for rapid oil spill remedy. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Khan, Farhan R; Syberg, Kristian; Shashoua, Yvonne; Bury, Nicolas R
2015-11-01
This study aimed to determine whether the uptake and localization of Ag in zebrafish was affected by the presence of polyethylene microplastic beads (PE MPBs). Zebrafish were exposed to 1 μg Ag L(-1) (radiolabelled with (110m)Ag) for 4 and 24 h in the presence or absence of PE MPBs (10, 100 or 1000 MPBs mL(-1)), and one treatment in which MPBs (1000 MPBs mL(-1)) were incubated with Ag to promote adsorption. The presence of MPBs, at any of the tested doses, had no effect on the uptake or localization of Ag. However, exposure to the Ag-incubated MPBs (∽75% of the Ag bound to MPBs) significantly reduced Ag uptake at both time points and also significantly increased the proportion of intestinal Ag. This study demonstrates that microplastics can alter the bioavailability and uptake route of a metal contaminant in a model fish species. Copyright © 2015 Elsevier Ltd. All rights reserved.
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2012-12-01
4.5 Food-grade aluminum foil 4.6 Stainless steel forceps 4.7 Single-edge razor blades 4.8 Teflon (or similar non-contaminating material) cutting...handling PE to avoid cross-contaminating the PE. 6.3 Methylene chloride (pesticide grade) rinsed, stainless steel forceps and scissors are used...3.1 PE is susceptible to contamination from atmospheric and surfaces, and so it must be handled using clean techniques. 3.2 While the formation of
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Si, Jianping; Sun, Yan; Wang, L U; Qin, Ying; Wang, Chongying; Wang, Xinyu
2016-12-01
DWF4 and CPD are key brassinosteroids (BRs) biosynthesis enzyme genes. To explore the function of Populus euphratica DWF4 (PeDWF4) and CPD (PeCPD), Arabidopsis thaliana transgenic lines (TLs) expressing PeDWF4, PeCPD or PeDWF4 plus PeCPD, namely PeDWF4-TL, PeCPD-TL and PeCP/DW-TL, were characterized. Compared with wild type (WT), the changes of both PeDWF4-TL and PeCPD-TL in plant heights, silique and hypocotyls lengths and seed yields were similar, but in bolting time and stem diameters, they were opposite. PeCP/DW-TL was more in plant heights and the lengths of primary root, silique, and fruit stalk, but less in silique numbers and seed yields than either PeDWF4-TL or PeCPD-TL. PeDWF4 and PeCPD specially expressed in PeDWF4-TL or PeCPDTL, and the transcription level of PeDWF4 was higher than that of PeCPD. In PeCP/DW-TL, their expressions were all relatively reduced. Additionally, the expression of PeDWF4 and PeCPD differentially made the expression levels of AtDWF4, AtCPD, AtBR6OX2, AtFLC, AtTCP1 and AtGA5 change in the TLs. The total BRs contents were PeDWF4-TL greater than PeCP/DW-TL greater than WT greater than PeCPD-TL. These results imply that PeDWF4 is functionally not exactly the same as PeCPD and there may be a synergistic and antagonistic effects in physiology between both of them in the regulation of plant growth and development.
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Controlled Emissivity Coatings to Delay Ignition of Polyethylene.
Sonnier, Rodolphe; Ferry, Laurent; Gallard, Benjamin; Boudenne, Abderrahim; Lavaud, François
2015-10-12
Semi-opaque to opaque films containing small amounts of various aluminium particles to decrease emissivity were easily prepared and coated onto low-density polyethylene (LDPE) sheets. The thermal-radiative properties (reflectivity, transmissivity and absorptivity) of the films were measured and related to the aluminum particles' content, size and nature. Time-to-ignition of samples was assessed using a cone calorimeter at different heat flux values (35, 50 and 75 kW/m²). The coatings allowed significant ignition delay and, in some cases, changed the material behaviour from thermally thin to thick behaviour. These effects are related both to their emissivity and transmissivity. A lower emissivity, which decreases during the degradation, and a lower transmissivity are the key points to ensure an optimal reaction-to-fire.
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NASA Astrophysics Data System (ADS)
Li, Wenfei; Chen, Yunxiang; Wu, Song; Zhang, Jian; Wang, Hao; Zeng, Dawen; Xie, Changsheng
2018-04-01
Silver coating as a broad-spectrum antimicrobial agent was considered to alleviate the inflammation caused by intrauterine device (IUD) in endometrium. In this work, to avoid the damage of silver coating and ensure its antibacterial properties, 3-aminopropyltrimethoxysilane (APTMS) was introduced to modify the polyethylene (PE) substrate for the purpose of improving the adhesion of the silver coating. From the 90° peel test, it could be found that the adhesive strength of silver coating on the APTMS modified PE substrate was nearly 23 times stronger than the silver coating on substrate without surface modification. The dramatically enhanced adhesive strength could be attributed to the formation of continuous chemical bonds between the silver coatings and substrates after surface modification, which had been confirmed by the XPS. Moreover, the standard antibacterial test revealed that the silver coated samples against Staphylococcus aureus (S. aureus) exhibit excellent antibacterial efficacy. Considering the largely enhanced adhesion and the effective antibacterial property, it is reasonable to believe that the silver coating could be considered as a potential candidate for the antibacterial agent in IUD.
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NASA Astrophysics Data System (ADS)
Hamsi, A.; Dinzi, R.
2017-03-01
Certain powder and others components can induce toxic reactions if not properly handled in the mixing stage. During handling, the small particles can become airborne and be trapped in the lungs, another concern is inhomogeneities in the mixing process. Uniform quantities of the particles of the components are needed in all portions of the mixture. This paper reports the results of mechanical properties studies of mixing three components formulation for mixing process. Contain of Polyethylene (PE), Polyprophylene (PP) and Aluminium Powder. Powder mixer, Autodesk mold flow and computer based on excell method was carried out to study the influence of each formulation component on the flow %, PE 20% and Aluminium powder 2%. Macroscopic optic and macro photo was carried out to identify the homogenity of mixing, tensile test for identify the strength of component after mixing. Finally the optimal tensile test with composition PP 785,PE 20% and Aluminium powder 2% at speed 52 rpm, temperature 1500C, the tensile strength 20,92 N/mm2. At temperature 1600C, speed 100 rpm the optimum tensile strength 17,91 N/mm2. The result of simulation autodesk mold flow adviser the filling time 6 seconds. Otherwise on manual hot hidraulic press the time of filling 10 seconds.
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NASA Astrophysics Data System (ADS)
Jumeau, Richard; Bourson, Patrice; Ferriol, Michel; Lahure, François; Ducos, Franck; Ligneron, Jérôme
2011-05-01
Polyethylene (PE) is a very important material. In 2008, almost 30% of the world plastics production was dedicated to this polymer (70 million tons) [1]. It is a consumer polymer because of its moderate cost of manufacturing and its physical and mechanical properties compatible with various applications in everyday life. Indeed, PE is generally easily processable. It possesses an excellent electric insulation and shock resistance combined with a very good chemical and biological inertia [2]. For each application, there is a particular grade, i.e. a polyethylene with well defined rheological properties. Therefore, it is essential to know how to differentiate these different grades by suitable methods of characterization. Differential Scanning Calorimetry (DSC) is one of the techniques usually used for this purpose. The knowledge of characteristic temperatures such as melting, cold crystallization or glass transition gives information on the viscosity and thus, on the grade of the polymer. DSC also allows the detection of defects, (for example, presence of unmelted pieces). However DSC is a tedious method for on-line quality control, limiting its scope. The determination of the polymer structure represents a major challenge in the industrial world of polymers. Raman spectroscopy, another technique of polymer analysis, is nowadays growing fast because of the advantages it presents. It is a non-destructive method, capable of also giving useful information about the morphology of the polymer. This technique can be perfectly used in industry by means of adapted sensors and devices with more and more reduced dimensions [3]. That technique is used to obtain the characteristic temperatures of PE and information on the polymer structure. The purpose of this article is to establish the correlation between the viscosity of a polymer and its characteristic temperatures obtained by DSC and subsequent possibilities of quality control in industry. These measurements are correlated
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Mountain, David; Keijzers, Gerben; Chu, Kevin; Joseph, Anthony; Read, Catherine; Blecher, Gabriel; Furyk, Jeremy; Bharat, Chrianna; Velusamy, Karthik; Munro, Andrew; Baker, Kylie; Kinnear, Frances; Mukherjee, Ahses; Watkins, Gina; Buntine, Paul; Livesay, Georgia; Fatovich, Daniel
2016-01-01
Overuse of CT Pulmonary Angiograms (CTPA) for diagnosing pulmonary embolism (PE), particularly in Emergency Departments (ED), is considered problematic. Marked variations in positive CTPA rates are reported, with American 4-10% yields driving most concerns. Higher resolution CTPA may increase sub-segmental PE (SSPE) diagnoses, which may be up to 40% false positive. Excessive use and false positives could increase harm vs. benefit. These issues have not been systematically examined outside America. To describe current yield variation and CTPA utilisation in Australasian ED, exploring potential factors correlated with variation. A retrospective multi-centre review of consecutive ED-ordered CTPA using standard radiology reports. ED CTPA report data were inputted onto preformatted data-sheets. The primary outcome was site level yield, analysed both intra-site and against a nominated 15.3% yield. Factors potentially associated with yield were assessed for correlation. Fourteen radiology departments (15 ED) provided 7077 CTPA data (94% ≥64-slice CT); PE were reported in 1028 (yield 14.6% (95%CI 13.8-15.4%; range 9.3-25.3%; site variation p <0.0001) with four sites significantly below and one above the 15.3% target. Admissions, CTPA usage, PE diagnosis rates and size of PE were uncorrelated with yield. Large PE (≥lobar) were 55% (CI: 52.1-58.2%) and SSPE 8.8% (CI: 7.1-10.5%) of positive scans. CTPA usage (0.2-1.5% adult attendances) was correlated (p<0.006) with PE diagnosis but not SSPE: large PE proportions. We found significant intra-site CTPA yield variation within Australasia. Yield was not clearly correlated with CTPA usage or increased small PE rates. Both SSPE and large PE rates were similar to higher yield historical cohorts. CTPA use was considerably below USA 2.5-3% rates. Higher CTPA utilisation was positively correlated with PE diagnoses, but without evidence of increased proportions of small PE. This suggests that increased diagnoses seem to be of
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Chu, Kevin; Joseph, Anthony; Read, Catherine; Blecher, Gabriel; Furyk, Jeremy; Bharat, Chrianna; Velusamy, Karthik; Munro, Andrew; Baker, Kylie; Kinnear, Frances; Mukherjee, Ahses; Watkins, Gina; Buntine, Paul; Livesay, Georgia
2016-01-01
Introduction Overuse of CT Pulmonary Angiograms (CTPA) for diagnosing pulmonary embolism (PE), particularly in Emergency Departments (ED), is considered problematic. Marked variations in positive CTPA rates are reported, with American 4–10% yields driving most concerns. Higher resolution CTPA may increase sub-segmental PE (SSPE) diagnoses, which may be up to 40% false positive. Excessive use and false positives could increase harm vs. benefit. These issues have not been systematically examined outside America. Aims To describe current yield variation and CTPA utilisation in Australasian ED, exploring potential factors correlated with variation. Methods A retrospective multi-centre review of consecutive ED-ordered CTPA using standard radiology reports. ED CTPA report data were inputted onto preformatted data-sheets. The primary outcome was site level yield, analysed both intra-site and against a nominated 15.3% yield. Factors potentially associated with yield were assessed for correlation. Results Fourteen radiology departments (15 ED) provided 7077 CTPA data (94% ≥64-slice CT); PE were reported in 1028 (yield 14.6% (95%CI 13.8–15.4%; range 9.3–25.3%; site variation p <0.0001) with four sites significantly below and one above the 15.3% target. Admissions, CTPA usage, PE diagnosis rates and size of PE were uncorrelated with yield. Large PE (≥lobar) were 55% (CI: 52.1–58.2%) and SSPE 8.8% (CI: 7.1–10.5%) of positive scans. CTPA usage (0.2–1.5% adult attendances) was correlated (p<0.006) with PE diagnosis but not SSPE: large PE proportions. Discussion/ Conclusions We found significant intra-site CTPA yield variation within Australasia. Yield was not clearly correlated with CTPA usage or increased small PE rates. Both SSPE and large PE rates were similar to higher yield historical cohorts. CTPA use was considerably below USA 2.5–3% rates. Higher CTPA utilisation was positively correlated with PE diagnoses, but without evidence of increased proportions
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Biodegradation of thermally treated low density polyethylene by fungus Rhizopus oryzae NS 5.
Awasthi, Shraddha; Srivastava, Neha; Singh, Tripti; Tiwary, D; Mishra, Pradeep Kumar
2017-05-01
Polythene is considered as one of the important object used in daily life. Being versatile in nature and resistant to microbial attack, they effectively cause environmental pollution. In the present study, biodegradation of low-density polyethylene (LDPE) have been performed using fungal lab isolate Rhizopus oryzae NS5. Lab isolate fungal strain capable of adhering to LDPE surface was used for the biodegradation of LDPE. This strain was identified as Rhizopus oryzae NS5 (Accession No. KT160362). Fungal growth was observed on the surface of the polyethylene when cultured in potato dextrose broth at 30 °C and 120 rpm, for 1 month. LDPE film was characterized before and after incubation by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and universal tensile machine. About 8.4 ± 3% decrease (gravimetrically) in weight and 60% reduction in tensile strength of polyethylene was observed. Scanning electron microscope analysis showed hyphal penetration and degradation on the surface of polyethylene. Atomic force microscope analysis showed increased surface roughness after treatment with fungal isolate. A thick network of fungal hyphae forming a biofilm was also observed on the surface of the polyethylene pieces. Present study shows the potential of Rhizopus oryzae NS5 in polyethylene degradation in eco friendly and sustainable manner.
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Middleton, L. Robert; Tarver, Jacob D.; Cordaro, Joseph; ...
2016-11-10
Melt state dynamics for a series of strictly linear polyethylenes with precisely spaced associating functional groups were investigated. The periodic pendant acrylic acid groups form hydrogen-bonded acid aggregates within the polyethylene (PE) matrix. The dynamics of these nanoscale heterogeneous morphologies were investigated from picosecond to nanosecond timescales by both quasi-elastic neutron scattering (QENS) measurements and fully atomistic molecular dynamics (MD) simulations. Two dynamic processes were observed. The faster dynamic processes which occur at the picosecond timescales are compositionally insensitive and indicative of spatially restricted local motions. The slower dynamic processes are highly composition dependent and indicate the structural relaxation ofmore » the polymer backbone. Higher acid contents, or shorter PE spacers between pendant acid groups, slow the structural relaxation timescale and increase the stretching parameter (β) of the structural relaxation. Additionally, the dynamics of specific hydrogen atom positions along the backbone correlate structural heterogeneity imposed by the associating acid groups with a mobility gradient along the polymer backbone. At time intervals (<2 ns), the mean-squared displacements for the four methylene groups closest to the acid groups are up to 10 times smaller than those of methylene groups further from the acid groups. At longer timescales acid aggregates rearrange and the chain dynamics of the slow, near-aggregate regions and the faster bridge regions converge, implying a characteristic timescale for the passage of chains between aggregates. As a result, the characterization of the nanoscale chain dynamics in these associating polymer systems both provides validation of simulation force fields and provides understanding of heterogeneous chain dynamics in associating polymers.« less
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Tribology of Langmuir-Blodgett Films
1992-03-01
poly - meric systems and the use of Langmuir - Blodgett films as lubricants. An, 1473 ESWnoW’oP’-oVsS osOLe UNCLASSIFIED SECUlRTV CLASSIFICATIONi O r ThIS...N/A N/A 4. TITLE (and Subtitle) S. TyPE OF REPORT & PERIOD COVERED Tribology of Langmuir - Blodgett Films Interim Technical Report 6. PERFORMING ORO...Co . - e o If neceesea mnd Identily by block number) Tribology, Langmuir - Blodgett Films 2 AerNACT t 44 Pem.e s* I peminp and tdolvart by block niber
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Ou, Li-Tse; Thomas, John E; Allen, L Hartwell; Vu, Joseph C; Dickson, Donald W
2006-08-01
This study was conducted to examine the effects of three application methods of metam sodium (broadcast, single irrigation drip tape delivery, and double irrigation drip tape delivery) and two plastic covers (polyethylene film and virtually impermeable film) on volatilization and on horizontal and vertical distributions of the biologically active product of metam sodium, methyl isothiocyanate (MITC), in field plots in a Florida sandy soil. Volatilization of MITC from field beds lasted for about 20 hours after completion of metam sodium application regardless of application methods. Virtually impermeable film (VIF) was a better barrier to reduce volatilization loss than polyethylene film (PE). Since water was not applied during broadcast application, MITC was mainly retained in the shallow soil layer (0- to 20-cm depth) and downward movement of MITC was limited to about 30 cm. Large values of standard deviation indicated that initial spatial distribution of MITC in the root zone (10- and 20-cm depths) of the two broadcast applied beds covered with PE or VIF was variable. Twice more water was delivered through the single drip tape than through individual tapes of double drip tape treatments during drip application of metam sodium. More water from the single drip tape likely facilitated downward movement of MITC to at least 60-cm depth, but MITC did not penetrate to this depth in the double drip tape beds. On the other hand, horizontal distribution of MITC in the root zone (10- and 20-cm depths) in the double drip tape beds was more uniform than in the single drip tape beds. More MITC was retained in the subsurface of the VIF-covered beds regardless of application methods than in the PE-covered beds.
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Kohay, Hagay; Sarisozen, Can; Sawant, Rupa; Jhaveri, Aditi; Torchilin, Vladimir P; Mishael, Yael G
2017-06-01
A novel drug delivery system for doxorubicin (DOX), based on organic-inorganic composites was developed. DOX was incorporated in micelles (M-DOX) of polyethylene glycol-phosphatidylethanolamine (PEG-PE) which in turn were adsorbed by the clay, montmorillonite (MMT). The nano-structures of the PEG-PE/MMT composites of LOW and HIGH polymer loadings were characterized by XRD, TGA, FTIR, size (DLS) and zeta measurements. These measurements suggest that for the LOW composite a single layer of polymer intercalates in the clay platelets and the polymer only partially covers the external surface, while for the HIGH composite two layers of polymer intercalate and a bilayer may form on the external surface. These nanostructures have a direct effect on formulation stability and on the rate of DOX release. The release rate was reversely correlated with the degree of DOX interaction with the clay and followed the sequence: M-DOX>HIGH formulation>LOW formulation>DOX/MMT. Despite the slower release from the HIGH formulation, its cytotoxicity effect on sensitive cells was as high as the "free" DOX. Surprisingly, the LOW formulation, with the slowest release, demonstrated the highest cytotoxicity in the case of Adriamycin (ADR) resistant cells. Confocal microscopy images and association tests provided an insight into the contribution of formulation-cell interactions vs. the contribution of DOX release rate. Internalization of the formulations was suggested as a mechanism that increases DOX efficiency, particularly in the ADR resistant cell line. The employment of organic-inorganic hybrid materials as drug delivery systems, has not reached its full potential, however, its functionality as an efficient tunable release system was demonstrated. DOX PEG-PE/clay formulations were design as an efficient drug delivery system. The main aim was to develop PEG-PE/clay formulations of different structures based on various PEG-PE/clay ratios in order to achieve tunable release rates, to control
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Wolf, C; Krivec, T; Blassnig, J; Lederer, K; Schneider, W
2002-02-01
The lifetime of articulating surfaces in joint endoprostheses made of ultra-high molecular weight polyethylene (UHMW-PE), especially of UHMW-PE-cups of hip-endoprostheses, is usually limited to 10-15 years due to material failure as a result of oxidation of the UHMW-PE in vivo. In this study the suitability of the natural antioxidant alpha-tocopherol (vitamin E) as a stabilizer for UHMW-PE in these applications was investigated. Specimens with 0.1%, 0.2%, 0.4% and 0.8% w/w alpha-tocopherol as well as unstabilized samples were sintered and sterilized with gamma-rays at 25 kGy in accordance with standard processing methods of cups for total hip-endoprostheses. These specimens were aged in pure oxygen at 70 degrees C and 5 bar as well as in aqueous H2O2 at 50 degrees C. The degree of oxidation was observed by means of FTIR-spectroscopy, DSC analysis and mechanical testing. The FTIR-measurements showed that alpha-tocopherol can prolong the lifetime of UHMW-PE in an oxidative environment by a factor of more than 2.5. In the mechanical tests no embrittlement could be observed with the stabilized samples. A comparison with the standard antioxidant system Irganox 1010/Irgafos 168 (Ciba-Geigy, Switzerland) was carried out and revealed that alpha-tocopherol can even exceed the stabilization effect of this widely-used antioxidant system.
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Fan, Bin; Liu, Lei; Li, Jun-Huan; Ke, Xi-Xian; Xu, Jun-Ting; Du, Bin-Yang; Fan, Zhi-Qiang
2016-01-07
Crystallization-driven self-assembly of polyethylene-b-poly(tert-butylacrylate) (PE-b-PtBA) block copolymers (BCPs) in N,N-dimethyl formamide (DMF) was studied. It is found that all three PE-b-PtBA BCPs used in this work can self-assemble into one-dimensional crystalline cylindrical micelles. When the BCP solution is cooled to crystallization temperature (Tc) from 130 °C, the seed micelles may be produced via two competitive processes in the initial period: stepwise micellization/crystallization and simultaneous crystallization/micellization. Subsequently, the seed micelles can undergo growth driven by the epitaxial crystallization of the unimers. The lengths of both the seed micelles and the grown micelles are longer for the BCP with a longer PtBA block at a higher Tc. Quasi-living growth of the PE-b-PtBA crystalline cylindrical micelles is achieved at a higher Tc. A longer PtBA block evidently retards the attachment of unimers to the crystalline micelles, leading to a slower growth rate.
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Controlled Emissivity Coatings to Delay Ignition of Polyethylene
Sonnier, Rodolphe; Ferry, Laurent; Gallard, Benjamin; Boudenne, Abderrahim; Lavaud, François
2015-01-01
Semi-opaque to opaque films containing small amounts of various aluminium particles to decrease emissivity were easily prepared and coated onto low-density polyethylene (LDPE) sheets. The thermal-radiative properties (reflectivity, transmissivity and absorptivity) of the films were measured and related to the aluminum particles’ content, size and nature. Time-to-ignition of samples was assessed using a cone calorimeter at different heat flux values (35, 50 and 75 kW/m2). The coatings allowed significant ignition delay and, in some cases, changed the material behaviour from thermally thin to thick behaviour. These effects are related both to their emissivity and transmissivity. A lower emissivity, which decreases during the degradation, and a lower transmissivity are the key points to ensure an optimal reaction-to-fire. PMID:28793609
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Cellular Behavior of Human Adipose-Derived Stem Cells on Wettable Gradient Polyethylene Surfaces
Ahn, Hyun Hee; Lee, Il Woo; Lee, Hai Bang; Kim, Moon Suk
2014-01-01
Appropriate surface wettability and roughness of biomaterials is an important factor in cell attachment and proliferation. In this study, we investigated the correlation between surface wettability and roughness, and biological response in human adipose-derived stem cells (hADSCs). We prepared wettable and rough gradient polyethylene (PE) surfaces by increasing the power of a radio frequency corona discharge apparatus with knife-type electrodes over a moving sample bed. The PE changed gradually from hydrophobic and smooth surfaces to hydrophilic (water contact angle, 90º to ~50º) and rough (80 to ~120 nm) surfaces as the power increased. We found that hADSCs adhered better to highly hydrophilic and rough surfaces and showed broadly stretched morphology compared with that on hydrophobic and smooth surfaces. The proliferation of hADSCs on hydrophilic and rough surfaces was also higher than that on hydrophobic and smooth surfaces. Furthermore, integrin beta 1 gene expression, an indicator of attachment, and heat shock protein 70 gene expression were high on hydrophobic and smooth surfaces. These results indicate that the cellular behavior of hADSCs on gradient surface depends on surface properties, wettability and roughness. PMID:24477265
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Infrared radiation of thin plastic films.
NASA Technical Reports Server (NTRS)
Tien, C. L.; Chan, C. K.; Cunnington, G. R.
1972-01-01
A combined analytical and experimental study is presented for infrared radiation characteristics of thin plastic films with and without a metal substrate. On the basis of the thin-film analysis, a simple analytical technique is developed for determining band-averaged optical constants of thin plastic films from spectral normal transmittance data for two different film thicknesses. Specifically, the band-averaged optical constants of polyethylene terephthalate and polyimide were obtained from transmittance measurements of films with thicknesses in the range of 0.25 to 3 mil. The spectral normal reflectance and total normal emittance of the film side of singly aluminized films are calculated by use of optical constants; the results compare favorably with measured values.
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NASA Astrophysics Data System (ADS)
Wang, J.; Guo, J. P.; Yi, J. J.; Huang, Q. G.; Li, H. M.; Li, Y. F.; Gao, K. J.; Yang, W. T.
2014-08-01
This paper reports the preparation of coral-shaped topological morphology nascent polyethylene (PE) particles promoted by the novel heterogeneous non-metallocene catalyst (m-CH3PhO)TiCl3/carbon nanotubes (CNTs), with AlEt3 used as a cocatalyst. Scanning electron microscope (SEM), high resolution transmission electron microscope (HR-TEM) and inductively coupled plasma (ICP) emission spectroscopy were used to determine the morphology of the catalyst particles and the content of (m-CH3PhO)TiCl3. The carbon nanotube surface was treated with Grignard Reagent prior to reacting with (m-CH3PhO)TiCl3. The catalyst system could effectively catalyze ethylene polymerization and ethylene with 1- hexene copolymerization, the catalytic activity could reach up to 5.8 kg/((gTi)h). Morphology of the obtained polymer particles by SEM and HR-TEM technique revealed that the nascent polyethylene particles looked like coral shape in micro-size. The multiwalled carbon nanotubes (MWCNTs) supported catalysts polymerized ethylene to form polymer nanocomposite in situ. The microscopic examination of this nanocomposite revealed that carbon nanoparticles in PE matrix had a good distribution and the cryogenically fractured surface was ductile-like when polymerization time was 2 min.
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Biodegradation of degradable plastic polyethylene by phanerochaete and streptomyces species.
Lee, B; Pometto, A L; Fratzke, A; Bailey, T B
1991-03-01
The ability of lignin-degrading microorganisms to attack degradable plastics was investigated in pure shake flask culture studies. The degradable plastic used in this study was produced commercially by using the Archer-Daniels-Midland POLYCLEAN masterbatch and contained pro-oxidant and 6% starch. The known lignin-degrading bacteria Streptomyces viridosporus T7A, S. badius 252, and S. setonii 75Vi2 and fungus Phanerochaete chrysosporium were used. Pro-oxidant activity was accelerated by placing a sheet of plastic into a drying oven at 70 degrees C under atmospheric pressure and air for 0, 4, 8, 12, 16, or 20 days. The effect of 2-, 4-, and 8-week longwave UV irradiation at 365 nm on plastic biodegradability was also investigated. For shake flask cultures, plastics were chemically disinfected and incubated-shaken at 125 rpm at 37 degrees C in 0.6% yeast extract medium (pH 7.1) for Streptomyces spp. and at 30 degrees C for the fungus in 3% malt extract medium (pH 4.5) for 4 weeks along with an uninoculated control for each treatment. Weight loss data were inconclusive because of cell mass accumulation. For almost every 70 degrees C heat-treated film, the Streptomyces spp. demonstrated a further reduction in percent elongation and polyethylene molecular weight average when compared with the corresponding uninoculated control. Significant (P < 0.05) reductions were demonstrated for the 4- and 8-day heat-treated films by all three bacteria. Heat-treated films incubated with P. chrysosporium consistently demonstrated higher percent elongation and molecular weight average than the corresponding uninoculated controls, but were lower than the corresponding zero controls (heat-treated films without 4-week incubation). The 2- and 4-week UV-treated films showed the greatest biodegradation by all three bacteria. Virtually no degradation by the fungus was observed. To our knowledge, this is the first report demonstrating bacterial degradation of these oxidized polyethylenes in
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Membranes and Films from Polymers.
ERIC Educational Resources Information Center
Blumberg, Avrom A.
1986-01-01
Provides background information on polymeric films and membranes including production methods, special industrial and medical applications, laboratory preparation, and an experimental investigation of a porous cellulose acetate membrane. Presents a demonstration to distinguish between high- and low-density polyethylene. (JM)
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Thermal transport in semicrystalline polyethylene by molecular dynamics simulation
NASA Astrophysics Data System (ADS)
Lu, Tingyu; Kim, Kyunghoon; Li, Xiaobo; Zhou, Jun; Chen, Gang; Liu, Jun
2018-01-01
Recent research has highlighted the potential to achieve high-thermal-conductivity polymers by aligning their molecular chains. Combined with other merits, such as low-cost, corrosion resistance, and light weight, such polymers are attractive for heat transfer applications. Due to their quasi-one-dimensional structural nature, the understanding on the thermal transport in those ultra-drawn semicrystalline polymer fibers or films is still lacking. In this paper, we built the ideal repeating units of semicrystalline polyethylene and studied their dependence of thermal conductivity on different crystallinity and interlamellar topology using the molecular dynamics simulations. We found that the conventional models, such as the Choy-Young's model, the series model, and Takayanagi's model, cannot accurately predict the thermal conductivity of the quasi-one-dimensional semicrystalline polyethylene. A modified Takayanagi's model was proposed to explain the dependence of thermal conductivity on the bridge number at intermediate and high crystallinity. We also analyzed the heat transfer pathways and demonstrated the substantial role of interlamellar bridges in the thermal transport in the semicrystalline polyethylene. Our work could contribute to the understanding of the structure-property relationship in semicrystalline polymers and shed some light on the development of plastic heat sinks and thermal management in flexible electronics.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Suh, Sungin; Kim, Jun-Rae; Kim, Seongkyung
2016-01-15
It has not been an easy task to deposit SiN at low temperature by conventional plasma-enhanced atomic layer deposition (PE-ALD) since Si organic precursors generally have high activation energy for adsorption of the Si atoms on the Si-N networks. In this work, in order to achieve successful deposition of SiN film at low temperature, the plasma processing steps in the PE-ALD have been modified for easier activation of Si precursors. In this modification, the efficiency of chemisorption of Si precursor has been improved by additional plasma steps after purging of the Si precursor. As the result, the SiN films preparedmore » by the modified PE-ALD processes demonstrated higher purity of Si and N atoms with unwanted impurities such as C and O having below 10 at. % and Si-rich films could be formed consequently. Also, a very high step coverage ratio of 97% was obtained. Furthermore, the process-optimized SiN film showed a permissible charge-trapping capability with a wide memory window of 3.1 V when a capacitor structure was fabricated and measured with an insertion of the SiN film as the charge-trap layer. The modified PE-ALD process using the activated Si precursor would be one of the most practical and promising solutions for SiN deposition with lower thermal budget and higher cost-effectiveness.« less
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Low-cost thin-film absorber/evaporator for an absorption chiller. Final report, May 1992-April 1993
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lowenstein, A.; Sibilia, M.
1993-04-01
The feasibility of making the absorber and evaporator of a small lithium-bromide absorption chiller from thin plastic films was studied. Tests were performed to measure (1) pressure limitations for a plastic thin-film heat exchanger, (2) flow pressure-drop characteristics, (3) air permeation rates across the plastic films, and (4) creep characteristics of the plastic films. Initial tests were performed on heat exchangers made of either low-density polyethylene (LDPE), high-density polyethylene (HDPE), or a LDPE/HDPE blend. While initial designs for the heat exchanger failed at internal pressures of only 5 to 6 psi, the final design could withstand pressures of 34 psi.
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Extrusion foaming of protein-based thermoplastic and polyethylene blends
NASA Astrophysics Data System (ADS)
Gavin, Chanelle; Lay, Mark C.; Verbeek, Casparus J. R.
2016-03-01
Currently the extrusion foamability of Novatein® Thermoplastic Protein (NTP) is being investigated at the University of Waikato in collaboration with the Biopolymer Network Ltd (NZ). NTP has been developed from bloodmeal (>86 wt% protein), a co-product of the meat industry, by adding denaturants and plasticisers (tri-ethylene glycol and water) allowing it to be extruded and injection moulded. NTP alone does not readily foam when sodium bicarbonate is used as a chemical blowing agent as its extensional viscosity is too high. The thermoplastic properties of NTP were modified by blending it with different weight fractions of linear low density polyethylene (LLDPE) and polyethylene grafted maleic anhydride (PE-g-MAH) compatibiliser. Extrusion foaming was conducted in two ways, firstly using the existing water content in the material as the blowing agent and secondly by adding sodium bicarbonate. When processed in a twin screw extruder (L/D 25 and 10 mm die) the material readily expanded due to the internal moisture content alone, with a conditioned expansion ratio of up to ± 0.13. Cell structure was non-uniform exhibiting a broad range cell sizes at various stages of formation with some coalescence. The cell size reduced through the addition of sodium bicarbonate, overall more cells were observed and the structure was more uniform, however ruptured cells were also visible on the extrudate skin. Increasing die temperature and introducing water cooling reduced cell size, but the increased die temperature resulted in surface degradation.
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NASA Astrophysics Data System (ADS)
Nagamatsu, Aiko; Casolino, Marco; Larsson, Oscar; Ito, Tsuyoshi; Yasuda, Nakahiro; Kitajo, Keiichi; Shimada, Ken; Takeda, Kazuo; Tsuda, Shuichi; Sato, Tatsuhiko
As a part of the Alteino Long Term Cosmic Ray measurements on board the International Space Station (ALTCRISS) project, the shielding effect of polyethylene (PE) were evaluated in the Russian segment of the ISS, using active and passive dosimeter systems covered with or without PE shielding. For the passive dosimeter system, PADLES (Passive Dosimeter for Life-Science and Experiments in Space) was used in the project, which consists of a Thermo-Luminescent Dosimeters (TLD) and CR-39 Plastic Nuclear Track Detectors (PNTDs) attached to a radiator. Not only CR-39 PNTD itself but also a tissue equivalent material, NAN-JAERI, were employed as the radiator in order to investigate whether CR-39 PNTD can be used as a surrogate of tissue equivalent material in space dosimetry or not. The agreements between the doses measured by PADLES with CR-39 PNTD and NAN-JAERI radiators were quite satisfactorily, indicating the tissue-equivalent dose can be measured by conventional PADLES even though CR-39 PNTD is not perfect tissue-equivalent material. It was found that the shielding effect of PE varies with location inside the spacecraft: it became less significant with an increase of the mean thickness of the wall. This tendency was also verified by Monte Carlo simulation using the PHITS code. Throughout the flight experiments, in a series of four phases in the ALTCRISS project from December 2005 to October 2007, we assessed the ability of PE to decrease radiation doses in Low Earth Orbit(LEO).
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What Is the PE Password? Incorporating Vocabulary in Your Elementary PE Program
ERIC Educational Resources Information Center
Robelee, Margaret E.
2016-01-01
This article describes a novel program for third through fifth grade called "What is the PE Password?" that teaches vocabulary words and concepts without sacrificing activity time in order to support Common Core learning.
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[RS3PE syndrome: presentation of two cases].
Parra Ródenas, J V; Calvo Catalá, J; González-Cruz Cervellera, M I; Cervera Moscardó, J; Valero Prieto, I
1996-12-01
Recently, the syndrome of remitting seronegative symmetrical synovitis with pitting edema (RS3PE), has been proposed. The RS3PE syndrome has an acute onset, does not produce bony erosions, with a predilection for elderly patients and an excellent prognosis. This condition distinguishing if from rheumatoid arthritis and polymyalgia rheumatica. The purpose is to call attention to a benign forms of arthritis in aging patients. We report two cases of RS3PE syndrome.
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Effects of Silica Nanostructures in Poly(ethylene oxide)-Based Composite Polymer Electrolytes.
Mohanta, Jagdeep; Anwar, Shahid; Si, Satyabrata
2016-06-01
The present work describes the synthesis of some poly(ethylene oxide)-based nanocomposite polymer electrolyte films using various silica nanostructures as the inorganic filler by simple solution mixing technique, in which the nature of the silica nanostructures play a vital role in modulating their electrochemical performances at room temperature. The silica nanostructures are prepared by ammonical hydrolysis of tetraethyl orthosilicate following the modified St6ber method. The resulting films are characterized by X-ray diffraction and differential scanning calorimeter to study their crystallinity. Room temperature AC impedance spectroscopy is utilized to determine the Li+ ion conductivity of the resulting films. The observed conductivity values of various NCPE films depend on the nature of silica filling as well as on their surface characteristics and also on the varying PEO-Li+ ratio, which is observed to be in the order of 10(-7)-10(-6) S cm(-1).
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Chang, C T; Zeng, F; Li, X J; Dong, W S; Lu, S H; Gao, S; Pan, F
2016-01-07
The simulation of synaptic plasticity using new materials is critical in the study of brain-inspired computing. Devices composed of Ba(CF3SO3)2-doped polyethylene oxide (PEO) electrolyte film were fabricated and with pulse responses found to resemble the synaptic short-term plasticity (STP) of both short-term depression (STD) and short-term facilitation (STF) synapses. The values of the charge and discharge peaks of the pulse responses did not vary with input number when the pulse frequency was sufficiently low(~1 Hz). However, when the frequency was increased, the charge and discharge peaks decreased and increased, respectively, in gradual trends and approached stable values with respect to the input number. These stable values varied with the input frequency, which resulted in the depressed and potentiated weight modifications of the charge and discharge peaks, respectively. These electrical properties simulated the high and low band-pass filtering effects of STD and STF, respectively. The simulations were consistent with biological results and the corresponding biological parameters were successfully extracted. The study verified the feasibility of using organic electrolytes to mimic STP.
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NASA Astrophysics Data System (ADS)
Chang, C. T.; Zeng, F.; Li, X. J.; Dong, W. S.; Lu, S. H.; Gao, S.; Pan, F.
2016-01-01
The simulation of synaptic plasticity using new materials is critical in the study of brain-inspired computing. Devices composed of Ba(CF3SO3)2-doped polyethylene oxide (PEO) electrolyte film were fabricated and with pulse responses found to resemble the synaptic short-term plasticity (STP) of both short-term depression (STD) and short-term facilitation (STF) synapses. The values of the charge and discharge peaks of the pulse responses did not vary with input number when the pulse frequency was sufficiently low(~1 Hz). However, when the frequency was increased, the charge and discharge peaks decreased and increased, respectively, in gradual trends and approached stable values with respect to the input number. These stable values varied with the input frequency, which resulted in the depressed and potentiated weight modifications of the charge and discharge peaks, respectively. These electrical properties simulated the high and low band-pass filtering effects of STD and STF, respectively. The simulations were consistent with biological results and the corresponding biological parameters were successfully extracted. The study verified the feasibility of using organic electrolytes to mimic STP.
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Equation of State and Damage in Polyethylene
DOE Office of Scientific and Technical Information (OSTI.GOV)
Coe, Joshua Damon; Brown, Eric; Cady, Carl Mcelhinney
The dynamic response of polymers differs significantly from those of metals, upon which many of the National Laboratories' deformation, damage, and failure models are based. Their moduli, yield strength, and damage characteristics are highly strain rate-, temperature-, and phase-dependent, requiring models that encompass a wide range of phenomena including some not in equilibrium. Recently, Los Alamos developed the Glassy Amorphous Polymer (GAP) 1 model [1] to address limitations in existing models of polymer deformation. GAP captures both volumetric (equation of state) and deviatoric (shear) response, including a non-equilibrium component to the former (a feature determined to be crucial in capturingmore » the low-pressure, viscoelastic response to impact loading). GAP has already been applied to polymers such as PMMA, PTFE, epoxy, and Kel-F 800, but with an emphasis on impact response as opposed to damage or failure. The current effort was launched to address this gap in predictive capability. For reasons that will be made clear, semi-crystalline polyethylene (PE) was chosen to serve as a model system for parameterization and validation. PE (-C 2H 4-)n is one of the most widely used polymers in industrial and engineering contexts, chiey due to the versatility of its mechanical response. This response can be tuned through network and chain structure, degree of crystallinity, and molecular weight. PE is found in several forms including low density (LDPE), high density (HDPE), and ultra-high molecular weight (UHMWPE). The focus here was on HDPE and UHMWPE, of pedigree described in the following section. Materials were well-characterized prior to study and are representative of semi-crystalline polymers of interest to DOE and DoD. Semi-crystalline PE undergoes a glass transition at low temperature (-35°C) and melts across a range of moderate temperatures (~80-180°C), depending on its structure. It is typically inert chemically, has low strength and high ductility
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Cossu, Andrea; Si, Yang; Sun, Gang; Nitin, Nitin
2017-08-11
Bacterial biofilm formation is linked to several infections and foodborne disease outbreaks. To address this challenge, there is an unmet need to develop rechargeable antimicrobial materials that can provide continuous sanitation of contact surfaces especially in the food industry. This study was aimed at evaluating a novel rechargeable antimicrobial polymer formed using PVA-co-PE with halamine functionality to prevent biofilm formation with repeated exposure to high loads of bacteria and organic content and also aid in inactivation of pre-formed biofilms upon contact with this novel material. Antibiofilm activity of this rechargeable antimicrobial material was evaluated using a combination of fluorescence and scanning electron microscopies and biofilm metabolic activity analyses. The results based on imaging and metabolic activity measurements demonstrated that halamine functionalized polymer films significantly reduced L. innocua and E. coli O157:H7 biofilms formation. This novel polymeric material maintained its antibiofilm activity with repeated cycles of extended exposure to high levels of bacterial load. These polymeric films were recharged using bleach and cleaned using mechanical sonication after each cycle of extended incubation with bacteria. Halamine functionalized polymeric material also exhibited significant antibacterial activity against pre-formed biofilms on a model surface. In summary, results demonstrate potential of this antimicrobial material to provide continuous sanitation surfaces and applications for inactivating pre-formed biofilms without extensive use of resources including water and heat. This polymeric material may be used as a replacement for existing polymeric materials or used as a coating on diverse materials. IMPORTANCE Conventional sanitizers can have limited efficacy in inactivating biofilms in areas with limited accessibility and buildup of organic biomass. Furthermore, none of the current approaches provide continuous
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Study of the degradation of mulch materials in vegetable crops for organic farming
NASA Astrophysics Data System (ADS)
María Moreno, Marta; Mancebo, Ignacio; Moreno, Carmen; Villena, Jaime; Meco, Ramón
2014-05-01
Mulching is the most common technique used worldwide by vegetable growers in protected cultivation. For this purpose, several plastic materials have been used, with polyethylene (PE) being the most widespread. However, PE is produced from petroleum derivatives, it is not degradable, and thus pollutes the environment for periods much longer than the crop duration (Martín-Closas and Pelacho, 2011), which are very important negative aspects especially for organic farmers. A large portion of plastic films is left on the field or burnt uncontrollably by the farmers, with the associated negative consequences to the environment (Moreno and Moreno, 2008). Therefore, the best solution is to find a material with a lifetime similar to the crop duration time that can be later incorporated by the agricultural system through a biodegradation process (Martín-Closas and Pelacho, 2011). In this context, various biodegradable materials have been considered as alternatives in the last few years, including oxo-biodegradable films, biopolymer mulches, different types of papers, and crop residues (Kasirajan and Ngouajio, 2012). In this work we evaluate the evolution of different properties related to mulch degradation in both the buried and the superficial (exposed) part of mulch materials of different composition (standard black PE, papers and black biodegradable plastics) in summer vegetable crops under organic management in Castilla-La Mancha (Central Spain). As results, it is remarkable the early deterioration suffered by the buried part of the papers, disappearing completely in the soil at the end of the crop cycles and therefore indicating the total incorporation of these materials to the soil once the crop has finished. In the case of the degradation of the exposed mulch, small differences between crops were observed. In general, all the materials were less degraded under the plants than when receiving directly the solar radiation. As conclusion, biodegradable mulches degrade
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-27
... Film, Sheet, and Strip (PET Film) From Taiwan: Extension of Time Limit for the Preliminary Results of... the antidumping duty order on PET Film from Taiwan covering the period July 1, 2010 through June 30... preliminary results of the administrative review of PET Film from Taiwan within this time limit. The...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-10
... Film, Sheet, and Strip (PET Film) From Taiwan: Extension of Time Limit for the Preliminary Results of... antidumping duty order on PET Film from Taiwan covering the period July 1, 2009, through June 30, 2010. See... preliminary results of the administrative review of PET Film from Taiwan within this time limit. Specifically...
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Biodegradation of Degradable Plastic Polyethylene by Phanerochaete and Streptomyces Species †
Lee, Byungtae; Pometto, Anthony L.; Fratzke, Alfred; Bailey, Theodore B.
1991-01-01
The ability of lignin-degrading microorganisms to attack degradable plastics was investigated in pure shake flask culture studies. The degradable plastic used in this study was produced commercially by using the Archer-Daniels-Midland POLYCLEAN masterbatch and contained pro-oxidant and 6% starch. The known lignin-degrading bacteria Streptomyces viridosporus T7A, S. badius 252, and S. setonii 75Vi2 and fungus Phanerochaete chrysosporium were used. Pro-oxidant activity was accelerated by placing a sheet of plastic into a drying oven at 70°C under atmospheric pressure and air for 0, 4, 8, 12, 16, or 20 days. The effect of 2-, 4-, and 8-week longwave UV irradiation at 365 nm on plastic biodegradability was also investigated. For shake flask cultures, plastics were chemically disinfected and incubated-shaken at 125 rpm at 37°C in 0.6% yeast extract medium (pH 7.1) for Streptomyces spp. and at 30°C for the fungus in 3% malt extract medium (pH 4.5) for 4 weeks along with an uninoculated control for each treatment. Weight loss data were inconclusive because of cell mass accumulation. For almost every 70°C heat-treated film, the Streptomyces spp. demonstrated a further reduction in percent elongation and polyethylene molecular weight average when compared with the corresponding uninoculated control. Significant (P < 0.05) reductions were demonstrated for the 4- and 8-day heat-treated films by all three bacteria. Heat-treated films incubated with P. chrysosporium consistently demonstrated higher percent elongation and molecular weight average than the corresponding uninoculated controls, but were lower than the corresponding zero controls (heat-treated films without 4-week incubation). The 2- and 4-week UV-treated films showed the greatest biodegradation by all three bacteria. Virtually no degradation by the fungus was observed. To our knowledge, this is the first report demonstrating bacterial degradation of these oxidized polyethylenes in pure culture. PMID:16348434
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Development of a fracture toughness test for balloon film
NASA Technical Reports Server (NTRS)
Tielking, John T.
1991-01-01
This paper describes the equipment and test procedures being developed in an ongoing project to measure J(c) for film in a biaxial stress state. The objective of the research is to confirm J(c) as a material property whose value will permit the initiation of film tear growth to be predicted. Results are presented for two polyethylene balloon films, an LDPE and LLDPE, of thickness 0.8 mil.
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Chain Ends and the Ultimate Tensile Strength of Polyethylene Fibers
NASA Astrophysics Data System (ADS)
O'Connor, Thomas C.; Robbins, Mark O.
Determining the tensile yield mechanisms of oriented polymer fibers remains a challenging problem in polymer mechanics. By maximizing the alignment and crystallinity of polyethylene (PE) fibers, tensile strengths σ ~ 6 - 7 GPa have been achieved. While impressive, first-principal calculations predict carbon backbone bonds would allow strengths four times higher (σ ~ 20 GPa) before breaking. The reduction in strength is caused by crystal defects like chain ends, which allow fibers to yield by chain slip in addition to bond breaking. We use large scale molecular dynamics (MD) simulations to determine the tensile yield mechanism of orthorhombic PE crystals with finite chains spanning 102 -104 carbons in length. The yield stress σy saturates for long chains at ~ 6 . 3 GPa, agreeing well with experiments. Chains do not break but always yield by slip, after nucleation of 1D dislocations at chain ends. Dislocations are accurately described by a Frenkel-Kontorova model, parametrized by the mechanical properties of an ideal crystal. We compute a dislocation core size ξ = 25 . 24 Å and determine the high and low strain rate limits of σy. Our results suggest characterizing such 1D dislocations is an efficient method for predicting fiber strength. This research was performed within the Center for Materials in Extreme Dynamic Environments (CMEDE) under the Hopkins Extreme Materials Institute at Johns Hopkins University. Financial support was provided by Grant W911NF-12-2-0022.
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Effect of the Crystal Structure on the Electrical Properties of Thin-Film PZT Structures
NASA Astrophysics Data System (ADS)
Delimova, L. A.; Gushchina, E. V.; Zaitseva, N. V.; Seregin, D. S.; Vorotilov, K. A.; Sigov, A. S.
2018-03-01
A new method of two-stage crystallization of lead zirconate-titanate (PZT) films using a seed sublayer with a low excess lead content has been proposed and realized. A seed layer with a strong texture of perovskite Pe(111) grains is formed from a solution with a lead excess of 0-5 wt %; the fast growth of the grains is provided by the deposition of the main film from a solution with high lead content. As a result, a strong Pe(111) texture with complete suppression of the Pe(100) orientation forms. An analysis of current-voltage dependences of the transient currents and the distributions of the local conductivity measured by the contact AFM method reveals two various mechanisms of current percolation that are determined by traps in the bulk and at the perovskite grain interfaces.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Pimputkar, S.M.; McCoy, J.K.; Stets, J.A.
1991-03-01
The integrity of a pipeline system is determined by its weakest links which may be the joints. Heat fusion is the most common method for joining gas distribution polyethylene (PE) piping. There are procedural, thermal, and mechanical aspects of making fusion joints. Acceptable procedural aspects, such as heater calibration and cleanliness, can be assured by rigorous training and certification of the operators. Thermal and mechanical aspects consist of specifying joining conditions such as the heater temperature, heating time, and joining pressure. In the absence of procedural errors, the strength of a fusion joint should depend on the pipe material, pipemore » dimensions, and the thermal and mechanical joining conditions. Socket heat fusion was studied both experimentally and analytically to determine how the strength of the joint varied with the conditions under which it was made. The standard tensile impact test was modified to test socket fusion joint samples in shear. The developed shear impact energy test data were found to be reliable measures of strength if the setup conditions were meticulously identical. A parameter, termed the socket joining parameter, was found to characterize the joining conditions. It is a strong function of melt volume at the end of the heating phase, and, physically, it is polyethylene transported parallel to the axis during insertion. The results for three resins are presented in the form of three nomographs. The nomographs may be used to select the required heater temperature or the heating time, for a given ambient temperature and a PE resin, to ensure a structurally sound socket heat fusion joint.« less
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Elementary Students' Construct of PE Teacher Credibility
ERIC Educational Resources Information Center
Ramos, Nilo O.; McCullick, Bryan A.
2015-01-01
The purpose of this study was to investigate elementary students' perceptions of PE teacher credibility. Eight high- and low-skilled students from grades 3 and 5 were selected from a school employing a PE teacher holding a National Board Certification. Data were collected in the school setting utilizing observations, field notes, an open-ended…
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Jairo A. Diaz; Julia L. Braun; Robert J. Moon; Jeffrey P. Youngblood
2015-01-01
Simultaneous control over optical and thermal properties is particularly challenging and highly desired in fields like organic electronics. Here we incorporated cellulose nanocrystals (CNCs) into polyethylene oxide (PEO) in an attempt to preserve the iridescent CNC optical reflection given by their chiral nematic organisation, while reducing the composite thermal...
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Marini, M; De Niederhausern, S; Iseppi, R; Bondi, M; Sabia, C; Toselli, M; Pilati, F
2007-04-01
Silver-doped organic-inorganic hybrid coatings were prepared starting from tetraethoxysilane- and triethoxysilane-terminated poly(ethylene glycol)-block-polyethylene by the sol-gel process. They were applied as a thin layer (0.6-1.1 microm) to polyethylene (PE) and poly(vinyl chloride) (PVC) films and the antibacterial activity of the coated films was tested against Gram-negative (Escherichia coli ATCC 25922) and Gram-positive (Staphylococcus aureus ATCC 6538) bacteria. The effect of several factors (such as organic-inorganic ratio, type of catalyst, time of post-curing, silver ion concentration, etc.) was investigated. Measurements at different contact times showed a rapid decrease of the viable count for both tested strains. The highest antibacterial activity [more than 6 log reduction within 6 h starting from 106 colony-forming units (cfu) mL-1] was obtained for samples with an organic-inorganic weight ratio of 80:20 and 5 wt % silver salt with respect to the coating. For the coatings prepared by an acid-catalyzed process, a high level of permanence of the antibacterial activity of the coated films was demonstrated by repeatedly washing the samples in warm water or by immersion in physiological saline solution at 37 degrees C for 3 days. The release of silver ions per square meter of coating is very similar to that previously observed for polyamides filled with metallic silver nanoparticles; however, when compared on the basis of Ag content, the concentration of silver ions released from the coating is much higher than that released from 1 mm thick specimens of polyamide (PA) filled with silver nanoparticles. Transparency and good adhesion of the coating to PE and PVC plastic substrates without any previous surface treatment are further interesting features.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-05
... DEPARTMENT OF COMMERCE International Trade Administration [C-533-825] Polyethylene Terephthalate... AGENCY: Import Administration, International Trade Administration, Department of Commerce. SUMMARY: The Department of Commerce (the Department) is conducting an administrative review under the countervailing duty...
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Zheng, Xiaoli; Xu, Qun; He, Linghao; Yu, Ning; Wang, Shanshan; Chen, Zhimin; Fu, JianWei
2011-05-19
Graphene oxide (GO) sheets were noncovalently modified with an amphiphilic double-crystalline block copolymer, polyethylene-b-poly(ethylene oxide) (PE-b-PEO) with assistance of supercritical CO(2) (SC CO(2)) in this work. The resulting PE-b-PEO/GO nanohybrids were characterized by transmission electron microscopy (TEM), wide-angle X-ray diffraction (WAXD), Fourier transform infrared spectroscopy (FTIR), and Raman spectra. Distinct morphologies of PE-b-PEO decorating on the surface of GO were obtained in different solvent systems and at different SC CO(2) pressures. We found that the solvent system and the SC CO(2) have significant influence on the crystallization, aggregation, or assembly behaviors of PE-b-PEO molecular chains on the GO sheets. The formation mechanism of the distinct nanohybrid structures is attributed to a relevant easy heteronucleation and the limited crystal growth of the block polymer on the surface of GO. The resulting modified GO sheets could find a broad spectrum of applications not only in producing graphene-based nanocomposites but also being used as a template to fabricate multifunctional structures due to the unique properties of PE-b-PEO. As a proof-of-concept, we further decorated the GO sheets with the as-prepared Au nanoparticles (Au NPs) and CdTe nanoparticles (CdTe NPs) with PE-b-PEO as the interlinker. Using the thiol-terminated PE-b-PEO as an interlinker, Au NPs can be densely assembled on the surface of GO via robust Au-S bonds. Furthermore, the photoluminescence quenching of CdTe NPs was more notable for PE-b-PEO/GO-CdTe hybrid compared to the GO-CdTe hybrid, suggesting that the electron transfer from the CdTe NPs to the GO sheets was enhanced with the PE-b-PEO interlinker. The availability of these affordable graphene-based multifunctional structures and their fundamental properties will open up new opportunities for nanoscience and nanotechnology and accelerate their applications. © 2011 American Chemical Society
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Kiran Ciliz, Nilgun; Ekinci, Ekrem; Snape, Colin E
2004-01-01
A comparison of waste and virgin polypropylene (PP) plastics under slow pyrolysis conditions is presented. Moreover, mixtures of waste PP with wastes of polyethylene (PE) and polystyrene (PS) were pyrolyzed under the same operating conditions. Not only the impact of waste on degradation products but also impacts of the variations in the mixing ratio were investigated. The thermogravimetric weight loss curves and their derivatives of virgin and waste PP showed differences due to the impurities which are dirt and food residues. The liquid yield distribution concerning the aliphatic, mono-aromatic and poly-aromatic compounds varies as the ratio of PP waste increases in the waste plastic mixtures. In addition to this, the alkene/alkane ratio of gas products shows variations depending on the mixing ratio of wastes.
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[Biodegradation of polyethylene].
Yang, Jun; Song, Yi-ling; Qin, Xiao-yan
2007-05-01
Plastic material is one of the most serious solid wastes pollution. More than 40 million tons of plastics produced each year are discarded into environment. Plastics accumulated in the environment is highly resistant to biodegradation and not be able to take part in substance recycle. To increase the biodegradation efficiency of plastics by different means is the main research direction. This article reviewed the recent research works of polyethylene biodegradation that included the modification and pretreatment of polyethylene, biodegradation pathway, the relevant microbes and enzymes and the changes of physical, chemical and biological properties after biodegradation. The study directions of exploiting the kinds of life-forms of biodegradation polyethylene except the microorganisms, isolating and cloning the key enzymes and gene that could produce active groups, and enhancing the study on polyethylene biodegradation without additive were proposed.
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Jungnickel, H; Pund, R; Tentschert, J; Reichardt, P; Laux, P; Harbach, H; Luch, A
2016-09-01
Plastic particles smaller than 5mm, so called microplastics have the capability to accumulate in rivers, lakes and the marine environment and therefore have begun to be considered in eco-toxicology and human health risk assessment. Environmental microplastic contaminants may originate from consumer products like body wash, tooth pastes and cosmetic products, but also from degradation of plastic waste; they represent a potential but unpredictable threat to aquatic organisms and possibly also to humans. We investigated exemplarily for polyethylene (PE), the most abundant constituent of microplastic particles in the environment, whether such fragments could be produced from larger pellets (2mm×6mm). So far only few analytical methods exist to identify microplastic particles smaller than 10μm, especially no imaging mass spectrometry technique. We used at first time-of-flight secondary ion mass spectrometry (ToF-SIMS) for analysis and imaging of small PE-microplastic particles directly in the model system Ottawa sand during exposure to sea surf simulation. As a prerequisite, a method for identification of PE was established by identification of characteristic ions for PE out of an analysis of grinded polymer samples. The method was applied onto Ottawa sand in order to investigate the influence of simulated environmental conditions on particle transformation. A severe degradation of the primary PE pellet surface, associated with the transformation of larger particles into smaller ones already after 14days of sea surf simulation, was observed. Within the subsequent period of 14days to 1month of exposure the number of detected smallest-sized particles increased significantly (50%) while the second smallest fraction increased even further to 350%. Results were verified using artificially degraded PE pellets and Ottawa sand. Copyright © 2016 Elsevier B.V. All rights reserved.
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Raman analysis of polyethylene glycols and polyethylene oxides
NASA Astrophysics Data System (ADS)
Sagitova, E. A.; Prokhorov, K. A.; Nikolaeva, G. Yu; Baimova, A. V.; Pashinin, P. P.; Yarysheva, A. Yu; Mendeleev, D. I.
2018-04-01
We present Raman study of commercial liquids and powders of polyethylene glycols and polyethylene oxides with the average molecular weight from 400 Da to 10000 kDa. The most significant spectral changes were observed for the range of the molecular weights, where the liquid/semisolid transition has occurred. For the powders we revealed increase in the content of the molecules in the helical conformation and in the content of the monoclinic crystalline phase with growth of the molecular weight.
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Meaningful Experiences in PE for All Students: An Activist Research Approach
ERIC Educational Resources Information Center
Walseth, Kristin; Engebretsen, Berit; Elvebakk, Lisbeth
2018-01-01
Background and purpose: The research literature in physical education (PE) is placing a growing focus on the need for research that can illuminate not only the challenges PE faces but also how we can develop PE to meet the needs of all students. The activist approach aims to study future possibilities in PE, and the goal is for all young people…
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RS3PE revealing recurrent non-Hodgkin's lymphoma.
Gisserot, Olivier; Crémades, Serge; Landais, Cécile; Leyral, Guénaelle; Bernard, Philippe; de Jauréguiberry, Jean-Pierre
2004-09-01
A patient meeting published criteria for remitting seronegative symmetrical synovitis with pitting edema (RS3PE) was found to have a synchronous recurrence of non-Hodgkin's malignant lymphoma. Reported cases of RS3PE associated with hematological malignancies and other forms of cancer are reviewed.
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Preparation and Conductivity Measurements of Thin Film (PEO)nZnCl2 Electrolyte System
NASA Astrophysics Data System (ADS)
Salehuddin, N.; Mohamad, A. A.; Alias, Y.
2010-03-01
We report zinc ion conducting thin film polymer based on non-volatile room temperature ionic liquid, with a zinc chloride dissolved in a water and blend with poly(ethylene) oxide in different ratio of salt. The resultant films are free standing, translucent, flexible and elastic. The conductivity measurement of the films was carried out at room temperature to find the highest conductivity films.
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Chang, C. T.; Zeng, F.; Li, X. J.; Dong, W. S.; Lu, S. H.; Gao, S.; Pan, F.
2016-01-01
The simulation of synaptic plasticity using new materials is critical in the study of brain-inspired computing. Devices composed of Ba(CF3SO3)2-doped polyethylene oxide (PEO) electrolyte film were fabricated and with pulse responses found to resemble the synaptic short-term plasticity (STP) of both short-term depression (STD) and short-term facilitation (STF) synapses. The values of the charge and discharge peaks of the pulse responses did not vary with input number when the pulse frequency was sufficiently low(~1 Hz). However, when the frequency was increased, the charge and discharge peaks decreased and increased, respectively, in gradual trends and approached stable values with respect to the input number. These stable values varied with the input frequency, which resulted in the depressed and potentiated weight modifications of the charge and discharge peaks, respectively. These electrical properties simulated the high and low band-pass filtering effects of STD and STF, respectively. The simulations were consistent with biological results and the corresponding biological parameters were successfully extracted. The study verified the feasibility of using organic electrolytes to mimic STP. PMID:26739613
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Making the Case for Developing New PE-for-Health Pedagogies
ERIC Educational Resources Information Center
Armour, Kathleen; Harris, Jo
2013-01-01
This article argues for a new direction in research on health education within physical education (PE). Governments are increasingly looking to schools as a convenient form of public health investment. PE is implicated in health because of its core focus on physical activity, but there is little evidence to suggest that PE improves health…
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Combating oil spill problem using plastic waste
DOE Office of Scientific and Technical Information (OSTI.GOV)
Saleem, Junaid, E-mail: junaidupm@gmail.com; Ning, Chao; Barford, John
Highlights: • Up-cycling one type of pollution i.e. plastic waste and successfully using it to combat the other type of pollution i.e. oil spill. • Synthesized oil sorbent that has extremely high oil uptake of 90 g/g after prolonged dripping of 1 h. • Synthesized porous oil sorbent film which not only facilitates in oil sorption but also increases the affinity between sorbent and oil by means of adhesion. - Abstract: Thermoplastic polymers (such as polypropylene, polyethylene, polyethylene terephthalate (PET) and high density polyethylene (HDPE)) constitute 5–15% of municipal solid waste produced across the world. A huge quantity of plasticmore » waste is disposed of each year and is mostly either discarded in landfills or incinerated. On the other hand, the usage of synthetic polymers as oil sorbents, in particular, polyolefins, including polypropylene (PP), and polyethylene (PE) are the most commonly used oil sorbent materials mainly due to their low cost. However, they possess relatively low oil absorption capacities. In this work, we provide an innovative way to produce a value-added product such as oil-sorbent film with high practical oil uptake values in terms of g/g from waste HDPE bottles for rapid oil spill remedy.« less
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Laboratory Analysis of Polymer Thin Films for Planetary Balloons and Gossamer Structures
NASA Technical Reports Server (NTRS)
Sterling, Jerry; Fairbrother, Debora A.
2004-01-01
Commercially available polymer thin fdms with thickness of 15 microns or less were evaluated for potential application as the gas envelope material of balloons and other inflated vehicles. Films on this thickness scale are of interest for Earth and Mars ballooning as well as many gossamer space structures. Due to the uniqueness of these missions relative to typical uses of these materials, application-specific materials properties measurements were made. We evaluated numerous polymer chemistries, plus a few variations within one chemistry. The data show that there are often trade-offs among the different materials, such as with polyesters and polyimides having greater stiffness (modulus) but lower tear propagation resistance than polyethylene. Sections of polyethylene films can be joined by heat sealing, while adhesives and their accompanying mass penalty must be used with polyesters and polyimides. When the analysis temperature is reduced to 190 K, polyethylenes display dramatically increased stiffness and yield point, while the increase for other materials is more modest. The data also show that manufacturing processes can significantly affect film properties. To emphasize the need for application-specific properties assessment, we discuss two recent applications using these materials.
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NASA Astrophysics Data System (ADS)
Elder, Robert M.; O'Connor, Thomas C.; Chantawansri, Tanya L.; Sliozberg, Yelena R.; Sirk, Timothy W.; Yeh, In-Chul; Robbins, Mark O.; Andzelm, Jan W.
2017-09-01
Semicrystalline polyethylene (PE) is attractive for a variety of mechanically demanding applications, where shock compression can occur. Although often highly crystalline, PE invariably contains nanoscale amorphous domains that influence shock propagation. Our objective in this work is to study the effects of such domains. To this end, we adopt a novel approach wherein we parametrize a simple continuum-level theory based on the shock impedance from molecular dynamics (MD) simulations. Using this theory, we predict how crystalline/amorphous interfaces attenuate shocks via energy reflection due to the impedance mismatch between the phases. The theory predicts that these interfaces attenuate weak shocks more effectively than strong shocks. We compare the theory to explicit nonequilibrium MD simulations of compressive shocks in semicrystalline PE containing nanometer-scale amorphous regions of varying size, where we analyze the pressure response and reflection of energy. The theory and simulations show good agreement for strong shocks (≥1.0 km /s ), but for weak shocks (<1.0 km /s ) the simulations show enhanced energy reflection relative to the continuum predictions. Furthermore, the simulations show an effect not captured by the continuum theory: the size of amorphous regions is important. The theory assumes a sharp (discontinuous) interface between two bulk phases and a sharp change in thermodynamic and hydrodynamic quantities at the shock front. However, the simulations show that when amorphous domains are narrow—with widths comparable to the shock front—reflection is reduced compared to the predictions. We identify several nanoscale mechanisms that reduce the impedance mismatch, and thus reduce reflection, at thin amorphous domains. First, the two-wave elastic-plastic structure of shocks in crystalline PE allows the faster-moving elastic precursor wave to compress small amorphous domains before the plastic wave arrives. Second, confinement between stiff
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Bioinspired Transparent Laminated Composite Film for Flexible Green Optoelectronics.
Lee, Daewon; Lim, Young-Woo; Im, Hyeon-Gyun; Jeong, Seonju; Ji, Sangyoon; Kim, Yong Ho; Choi, Gwang-Mun; Park, Jang-Ung; Lee, Jung-Yong; Jin, Jungho; Bae, Byeong-Soo
2017-07-19
Herein, we report a new version of a bioinspired chitin nanofiber (ChNF) transparent laminated composite film (HCLaminate) made of siloxane hybrid materials (hybrimers) reinforced with ChNFs, which mimics the nanofiber-matrix structure of hierarchical biocomposites. Our HCLaminate is produced via vacuum bag compressing and subsequent UV-curing of the matrix resin-impregnated ChNF transparent paper (ChNF paper). It is worthwhile to note that this new type of ChNF-based transparent substrate film retains the strengths of the original ChNF paper and compensates for ChNF paper's drawbacks as a flexible transparent substrate. As a result, compared with high-performance synthetic plastic films, such as poly(ethylene terephthalate), poly(ether sulfone), poly(ethylene naphthalate), and polyimide, our HCLaminate is characterized to exhibit extremely smooth surface topography, outstanding optical clarity, high elastic modulus, high dimensional stability, etc. To prove our HCLaminate as a substrate film, we use it to fabricate flexible perovskite solar cells and a touch-screen panel. As far as we know, this work is the first to demonstrate flexible optoelectronics, such as flexible perovskite solar cells and a touch-screen panel, actually fabricated on a composite film made of ChNF. Given its desirable macroscopic properties, we envision our HCLaminate being utilized as a transparent substrate film for flexible green optoelectronics.
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Urban Waters and the Caño Martín Peña (Martín Peña Channel, Puerto Rico)
The Martín Peña Channel Urban Waters Federal Partnership seeks to make significant contributions to the health and welfare of the eight communities that surround the Martín Peña Channel in San Juan, Puerto Rico.
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Nanoparticle–Film Plasmon Ruler Interrogated with Transmission Visible Spectroscopy
2015-01-01
The widespread use of plasmonic nanorulers (PNRs) in sensing platforms has been plagued by technical challenges associated with the development of methods to fabricate precisely controlled nanostructures with high yield and characterize them with high throughput. We have previously shown that creating PNRs in a nanoparticle–film (NP–film) format enables the fabrication of an extremely large population of uniform PNRs with 100% yield using a self-assembly approach, which facilitates high-throughput PNR characterization using ensemble spectroscopic measurements and eliminates the need for expensive microscopy systems required by many other PNR platforms. We expand upon this prior work herein, showing that the NP–film PNR can be made compatible with aqueous sensing studies by adapting it for use in a transmission localized surface plasmon resonance spectroscopy format, where the coupled NP–film resonance responsible for the PNR signal is directly probed using an extinction measurement from a standard spectrophotometer. We designed slide holders that fit inside standard spectrophotometer cuvettes and position NP–film samples so that the coupled NP–film resonance can be detected in a collinear optical configuration. Once the NP–film PNR samples are cuvette-compatible, it is straightforward to calibrate the PNR in aqueous solution and use it to characterize dynamic, angstrom-scale distance changes resulting from pH-induced swelling of polyelectrolyte (PE) spacer layers as thin as 1 PE layer and also of a self-assembled monolayer of an amine-terminated alkanethiol. This development is an important step toward making PNR sensors more user-friendly and encouraging their widespread use in various sensing schemes. PMID:25541618
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Pimputkar, S.M.; McCoy, J.K.; Stets, J.A.
1991-03-01
The integrity of a pipeline system is determined by its weakest links which may be the joints. Heat fusion is the most common method for joining gas distribution polyethylene (PE) piping. There are procedural, thermal, and mechanical aspects of making fusion joints. Acceptable procedural aspects, such as heater calibration and cleanliness, can be assured by rigorous training and certification of the operators. Thermal and mechanical aspects consist of specifying joining conditions such as the heater temperature, heating time, and joining pressure. In the absence of procedural errors, the strength of a fusion joint should depend on the pipe material, pipemore » dimensions, and the thermal and mechanical joining conditions. Socket heat fusion was studied both experimentally and analytically to determine how the strength of the joint varied with the conditions under which it was made. The standard tensile impact test was modified to test socket fusion joint samples in shear. The developed shear impact energy test data were found to be reliable measures of strength if the setups for conditions were meticulously identical. A parameter, termed the socket joining parameter, was found to characterize the joining conditions. It is a strong function of melt volume at the end of the heating phase, and physically, it is polyethylene transported parallel to the axis during insertion. The results for three resins are presented in the form of three nomographs. The nomographs may be used to select the required heater temperature or the heating time, for a given ambient temperature and a PE resin, to ensure a structurally sound socket heat fusion joint.« less
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Merinska, D.; Kalendova, A.; Tesarikova, A.
2014-05-15
Nanocomposite materials with layered clay used as nanofiller and polyethylene (PE), polypropylene (PP) and copolymer ethylene and vinyl acetate matrix (EVA, the content of VA component 19 wt. %) were prepared by compounding the individual components in Brabender kneader. The MMT Na+ and four types of commercial products such as Nanofil N 5 and N3000, Cloisite 93A and 30B were used as nanofillers. Next to the clays microprecipitated CaHCO{sub 3}, nanosilica and Halloysite tubes were used. The quantity of all the above-mentioned (nano)fillers was 1, 3 and 5 wt. % in relation to the content of montmorillonite. The aim wasmore » to evaluate the influence of (nano)filler type and concentration on nanocomposite barrier properties. The morphology of nanocomposite samples was examined by means of XRD analysis illustrated by transmission electronic microscopy TEM. Furthermore, permeability for O{sub 2} and CO{sub 2} were observed.« less
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Triblock copolymer micelles as templates for preparation of mesoporous niobia thin films
NASA Astrophysics Data System (ADS)
Georgiev, R.; Christova, D.; Todorova, L.; Georgieva, B.; Vasileva, M.; Novakov, Ch; Babeva, T.
2018-03-01
The micelle formation of commercially available Pluronic PE 6800 (PEO-PPO-PEO triblock copolymer) was studied by means of a dye solubilization method, and the solubility of 1,6-diphenyl-1,3,5-hexatriene in aqueous solutions of the copolymer with concentrations ranging from 0.05 to 20 % w/v was studied by recording the transmission and emission spectra of the solutions using UV-VIS and photoluminescence spectroscopy, respectively. Further, mesoporous Nb2O5 films using PE 6800 micelles templates were obtained through sol-gel using spin-coating; their morphology, structure and optical properties were studied by TEM, SAED and nonlinear fitting of reflectance measurements. The possible application of the films in optical sensing of vapors was demonstrated and discussed.
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Thin Films of Novel Linear-Dendritic Diblock Copolymers
NASA Astrophysics Data System (ADS)
Iyer, Jyotsna; Hammond, Paula
1998-03-01
A series of diblock copolymers with one linear block and one dendrimeric block have been synthesized with the objective of forming ultrathin film nanoporous membranes. Polyethyleneoxide serves as the linear hydrophilic portion of the diblock copolymer. The hyperbranched dendrimeric block consists of polyamidoamine with functional end groups. Thin films of these materials made by spin casting and the Langmuir-Blodgett techniques are being studied. The effect of the polyethylene oxide block size and the number and chemical nature of the dendrimer end group on the nature and stability of the films formed willbe discussed.
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Modulation of the Activity of Mycobacterium tuberculosis LipY by Its PE Domain
Garrett, Christopher K.; Broadwell, Lindsey J.; Hayne, Cassandra K.; Neher, Saskia B.
2015-01-01
Mycobacterium tuberculosis harbors over 160 genes encoding PE/PPE proteins, several of which have roles in the pathogen’s virulence. A number of PE/PPE proteins are secreted via Type VII secretion systems known as the ESX secretion systems. One PE protein, LipY, has a triglyceride lipase domain in addition to its PE domain. LipY can regulate intracellular triglyceride levels and is also exported to the cell wall by one of the ESX family members, ESX-5. Upon export, LipY’s PE domain is removed by proteolytic cleavage. Studies using cells and crude extracts suggest that LipY’s PE domain not only directs its secretion by ESX-5, but also functions to inhibit its enzymatic activity. Here, we attempt to further elucidate the role of LipY’s PE domain in the regulation of its enzymatic activity. First, we established an improved purification method for several LipY variants using detergent micelles. We then used enzymatic assays to confirm that the PE domain down-regulates LipY activity. The PE domain must be attached to LipY in order to effectively inhibit it. Finally, we determined that full length LipY and the mature lipase lacking the PE domain (LipYΔPE) have similar melting temperatures. Based on our improved purification strategy and activity-based approach, we concluded that LipY’s PE domain down-regulates its enzymatic activity but does not impact the thermal stability of the enzyme. PMID:26270534
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NASA Technical Reports Server (NTRS)
Trigwell, Steve; Boucher, Derrick; Calle, Carlos
2006-01-01
The use of an atmospheric pressure glow discharge (APGD) plasma was used at KSC to increase the hydrophilicity of spaceport materials to enhance their surface charge dissipation and prevent possible ESD in spaceport operations. Significant decreases in charge decay times were observed after tribocharging the materials using the standard KSC tribocharging test. The polarity and amount of charge transferred was dependent upon the effective work function differences between the respective materials. In this study, polyethylene (PE) and polytetrafluoroethylene (PTFE) were exposed to a He+O2 APGD. The pre and post treatment surface chemistry was analyzed by X-ray photoelectron spectroscopy and contact angle measurements. Semi-empirical and ab initio calculations were performed to correlate the experimental results with some plausible molecular and electronic structure features of the oxidation process. For the PE, significant surface oxidation was observed, as indicated by XPS showing C-O, C=O, and O-C=O bonding, and a decrease in the surface contact angle from 98.9 deg to 61.2 deg. For the PTFE, no C-O bonding appeared and the surface contact angle increased indicating the APGD only succeeded in cleaning the PTFE surface without affecting the surface structure. The calculations using the PM3 and DFT methods were performed on single and multiple oligomers to simulate a wide variety of oxidation scenarios. Calculated work function results suggest that regardless of oxidation mechanism, e.g. -OH, =0 or a combination thereof, the experimentally observed levels of surface oxidation are unlikely to lead to a significant change in the electronic structure of PE and that its increased hydrophilic properties are the primary reason for the observed changes in its electrostatic behavior. The calculations for PTFE argue strongly against significant oxidation of that material, as confirmed by the XPS results.
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Tcaciuc, A Patricia; Apell, Jennifer N; Gschwend, Philip M
2015-12-01
Understanding the transfer of chemicals between passive samplers and water is essential for their use as monitoring devices of organic contaminants in surface waters. By applying Fick's second law to diffusion through the polymer and an aqueous boundary layer, the authors derived a mathematical model for the uptake of chemicals into a passive sampler from water, in finite and infinite bath conditions. The finite bath model performed well when applied to laboratory observations of sorption into polyethylene (PE) sheets for various chemicals (polycyclic aromatic hydrocarbons, polychlorinated biphenyls [PCBs], and dichlorodiphenyltrichloroethane [DDT]) and at varying turbulence levels. The authors used the infinite bath model to infer fractional equilibration of PCB and DDT analytes in field-deployed PE, and the results were nearly identical to those obtained using the sampling rate model. However, further comparison of the model and the sampling rate model revealed that the exchange of chemicals was inconsistent with the sampling rate model for partially or fully membrane-controlled transfer, which would be expected in turbulent conditions or when targeting compounds with small polymer diffusivities and small partition coefficients (e.g., phenols, some pesticides, and others). The model can be applied to other polymers besides PE as well as other chemicals and in any transfer regime (membrane, mixed, or water boundary layer-controlled). Lastly, the authors illustrate practical applications of this model such as improving passive sampler design and understanding the kinetics of passive dosing experiments. © 2015 SETAC.
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Method for shaping polyethylene tubing
NASA Technical Reports Server (NTRS)
Kramer, R. C.
1981-01-01
Method forms polyethylene plastic tubing into configurations previously only possible with metal tubing. By using polyethylene in place of copper or stain less steel tubing inlow pressure systems, fabrication costs are significantly reduced. Polyethylene tubing can be used whenever low pressure tubing is needed in oil operations, aircraft and space applications, powerplants, and testing laboratories.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-09
... DEPARTMENT OF COMMERCE International Trade Administration [C-533-825] Polyethylene Terephthalate...: Import Administration, International Trade Administration, Department of Commerce. SUMMARY: On August 1, 2011, the Department of Commerce (the Department) issued the preliminary results of the administrative...
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FTIR studies on the effect of concentration of polyethylene glycol on polimerization of Shellac
NASA Astrophysics Data System (ADS)
Khairuddin; Pramono, E.; Utomo, S. B.; Wulandari, V.; Zahrotul W, A.; Clegg, F.
2016-11-01
In the present paper, it was reported the FTIR studies on the efect of polyethylene glycol on polimerization of shellac. The shellac was shellac waxfree, and the solvent was ethanol 96%. The shellac films were were prepared by solvent- evaporation method. The concentrations of polyethylene glycol having molecular weight of 400 were 10, 30, 60, and 90 w/w %. Three peak intensity bands of C= O stretching of ester at 1709 cm-1, O-H stretching of hydroxyl group at 3400 cm-1, and C-H stretching vibration at 2942 cm-1 were observed and related to polimerization of shellac. It was found that polymerization of shellac was slowed down by polyethyelene glycol, and the degree of polymerization of shellac decreased with increasing the concentration of polyethyelene glycol.
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ERIC Educational Resources Information Center
Vandertie, Joan; Corner, Amy B.; Corner, Kevin J.
2012-01-01
Marana Middle School in Tucson, Ariz., scrapped its traditional P.E. program that emphasized team sports and shifted to a program that focuses on lifetime fitness, student choice in activities, and nutrition and health education. The program also includes student leadership development and informal community service. As a result, Marana students…
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NASA Astrophysics Data System (ADS)
Wang, Jian
2017-01-01
In order to change traditional PE teaching mode and realize the interconnection, interworking and sharing of PE teaching resources, a distance PE teaching platform based on broadband network is designed and PE teaching information resource database is set up. The designing of PE teaching information resource database takes Windows NT 4/2000Server as operating system platform, Microsoft SQL Server 7.0 as RDBMS, and takes NAS technology for data storage and flow technology for video service. The analysis of system designing and implementation shows that the dynamic PE teaching information resource sharing platform based on Web Service can realize loose coupling collaboration, realize dynamic integration and active integration and has good integration, openness and encapsulation. The distance PE teaching platform based on Web Service and the design scheme of PE teaching information resource database can effectively solve and realize the interconnection, interworking and sharing of PE teaching resources and adapt to the informatization development demands of PE teaching.
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Duncan, R A; Stapleton, J J; McKenry, M V
1992-12-01
Placement of a 3-m-wide, black, polyethylene film mulch down rows of peach (Prunus persica 'Red Haven' on 'Lovell' rootstock) and almond (Prunus dulcis 'Nonpareil' on 'Lovell') trees in the San Joaquin Valley of California resulted in irrigation water conservation of 75%, higher soil temperature in the surface 30 cm, a tendency toward greater root mass, elimination of weeds, and a greater abundance of Meloidogyne incognita second-stage juveniles in soil but reduced root galling when compared to the nonmulched control. Population levels of Pratylenchus hexincisus, a nematode found within tree roots, were reduced by mulching, as were those of Tylenchulus semipenetrans, which survived on old grape roots remaining from a previously planted vineyard, and Paratrichodorus minor, which probably fed on roots of various weed species growing in the nonmulched soil. Populations of Pythium ultimum were not significantly changed, probably also due to the biological refuge of the old grape roots and moderate soil heating level. Trunk diameters of peach trees were increased by mulching, but those of almond trees were reduced by the treatment. Leaf petiole analysis indicated that concentrations of mineral nutrients were inconsistent, except for a significant increase in Ca in both tree species.
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Nath, Caroline Daiane; Neres, Marcela Abbado; Scheidt, Kácia Carine; Bersot, Luciano Dos Santos; Sunahara, Samantha Mariana Monteiro; Sarto, Jaqueline Rocha Wobeto; Stangarlin, José Renato; Gomes, Simone Damasceno; Sereno, Mallu Jagnow; Perin, Ana Paula
2018-03-02
The objective was to characterize the fermentative and microbiological profile of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time. The experimental design consisted of a randomized block design with four and six wrapping layers (100 and 150 microns in total. respectively) allocated in the main plots, through repeated measures analysis (30, 60, and 90 days of storage) with four replicates. The storage time and number of wrapping layers did not show changes in the population of Clostridium and lactic acid bacteria. A decrease was observed in the enterobacteria population with an increase in the storage period in the two wrapping layers studied. Upon opening of the haylage at 30 days, the population of Bacillus was lower in haylages made with six layers of wrapping (3.63 log colony forming units (CFU) g-1). No growth of Listeria sp. or Salmonella sp. was observed during the experimental period. The fungal genera with greater occurrence were Penicillium sp. and Fusarium sp. The following mycotoxins were not detected: ochratoxin A, fumonisins, and zearalenone. Relative to the organic butyric, propionic, and acetic acids, the haylages presented a low concentration of lactic acid; this may have prevented a drop in the pH, which was high when the silos were opened (5.4). The levels of ammoniacal nitrogen and soluble carbohydrates presented no variation among the number of wrapping layers, with an overall average of 35.55 and 38.04 g kg-1. Tifton 85 bermudagrass haylage wrapped with four and six layers presented adequate fermentation and microbiological characteristics in the evaluated periods.
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High rate chemical vapor deposition of carbon films using fluorinated gases
Stafford, Byron L.; Tracy, C. Edwin; Benson, David K.; Nelson, Arthur J.
1993-01-01
A high rate, low-temperature deposition of amorphous carbon films is produced by PE-CVD in the presence of a fluorinated or other halide gas. The deposition can be performed at less than 100.degree. C., including ambient room temperature, with a radio frequency plasma assisted chemical vapor deposition process. With less than 6.5 atomic percent fluorine incorporated into the amorphous carbon film, the characteristics of the carbon film, including index of refraction, mass density, optical clarity, and chemical resistance are within fifteen percent (15%) of those characteristics for pure amorphous carbon films, but the deposition rates are high.
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Pascaud, R S; Evans, W T; McCullagh, P J; FitzPatrick, D P
1997-05-01
Surface damage of the tibial plateau components of knee prostheses made from medical grade ultra-high-molecular-weight polyethylene (UHMW-PE) has been attributed to delamination wear caused by a fatigue fracture mechanism. It has been proposed that factors such as component design and method of sterilization contribute to such failure mechanisms. Understanding the fracture behaviour of UHMW-PE is therefore critical in optimizing the in vivo life-span of total joint components. The elastic-plastic fracture toughness parameter J was consequently determined for a commercial UHMW-PE at ambient and body temperatures, before and after gamma-irradiation sterilization in air at a minimum dose of 29 kGy. Both ductile stability theory and experimental data suggest that cracks propagate in a stable manner, although stability is affected by the sterilization process. Sterilization with gamma-irradiation results in a loss in fracture toughness JIc of 50% and a decrease in tearing modulus (Tm) of 30%. This dramatic reduction could result in a 50% decrease in the residual strength of the components, maximum permissible crack size under service loading and service life (assuming flaws such as fusion defects exist). The time required for a crack to grow from its original size to the maximum permissible size could be decreased by 30%, resulting in earlier failure. In terms of the design of joint replacement components the critical factor to envisage is the design stress level, which should be halved to account for the irradiation process. A scanning electron microscope study reveals that the material fails in layers parallel to the fracture surface.
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2016-01-01
The aim of this study was to determine how representative wear scars of simulator-tested polyethylene (PE) inserts compare with retrieved PE inserts from total knee replacement (TKR). By means of a nonparametric self-organizing feature map (SOFM), wear scar images of 21 postmortem- and 54 revision-retrieved components were compared with six simulator-tested components that were tested either in displacement or in load control according to ISO protocols. The SOFM network was then trained with the wear scar images of postmortem-retrieved components since those are considered well-functioning at the time of retrieval. Based on this training process, eleven clusters were established, suggesting considerable variability among wear scars despite an uncomplicated loading history inside their hosts. The remaining components (revision-retrieved and simulator-tested) were then assigned to these established clusters. Six out of five simulator components were clustered together, suggesting that the network was able to identify similarities in loading history. However, the simulator-tested components ended up in a cluster at the fringe of the map containing only 10.8% of retrieved components. This may suggest that current ISO testing protocols were not fully representative of this TKR population, and protocols that better resemble patients' gait after TKR containing activities other than walking may be warranted. PMID:27597955
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Amyloid arthropathy revealed by RS3PE syndrome.
Magy, N; Michel, F; Auge, B; Toussirot, E; Wendling, D
2000-01-01
Amyloid arthropathy is a form of primary AL amyloidosis with a monoclonal component in the blood and/or urine, and RS3PE syndrome is acute edematous polysynovitis in subjects older than 60 years. A 74-year-old man was diagnosed with both disorders. He was admitted for benign acute polyarthritis of the hands and feet and reported carpal tunnel symptoms predominating on the right. A synovial biopsy at the right wrist disclosed deposits that stained with Congo red even after potassium permanganate treatment (positive Wright's test). Articular AL amyloidosis was diagnosed. The symptoms resolved under glucocorticoid therapy alone, casting some doubt on their relationship with the amyloidosis. Roentgenograms showed geodes, a feature not present in RS3PE. Whether RS3PE may be among the possible presentations of articular amyloidosis is discussed.
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Weiyu, Cao; Tashiro, Kohji; Hanesaka, Makoto; Takeda, Shinichi; Masunaga, Hiroyasu; Sasaki, Sono; Takata, Masaki
2009-02-26
The phase transition behaviors of low-molecular-weight polyethylene-poly(ethylene oxide) (PE-b-PEO) diblock copolymers with the monomeric units of PE/PEO = 17/40 and 39/86 have been successfully investigated through the temperature-dependent measurements of wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), infrared and Raman spectra, as well as thermal analysis. These diblock copolymers had been believed to show only order-to-disorder transition of lamellar morphology in a wide temperature region, but it has been found here for the first time that this copolymer clearly exhibits the three stages of transitions among lamella, gyroid, cylinder, and spherical phases in the heating and cooling processes. The WAXD and IR/Raman spectral measurements allowed us to relate these morphological changes to the microscopic changes in the aggregation states of PEO and PE segments. In the low-temperature region the PEO segments form the monoclinic crystal of (7/2) helical chain conformation and the PE segments of planar-zigzag form take the orthorhombic crystalline phase. These crystalline lamellae of PEO and PE segments are alternately stacked with the long period of 165 Angstroms. In a higher temperature region, where the PEO crystalline parts are on the way of melting but the PE parts are still in the orthorhombic phase, the gyroid morphology is detected in the SAXS data. By heating further, the gyroid morphology changes to the hexagonally packed cylindrical morphology, where the orthorhombic phase of PE segments is gradually disordered because of thermally activated molecular motion and finally transforms to the pseudohexagonal or rotator phase. Once the PE segments are perfectly melted, the higher-order structure changes from the cylinder to the spherical morphology. These morphological transitions might relate to the thermally activated motions of two short chain segments of the diblock copolymer, although the details of the transition mechanism are
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Yamada, W.I.; Faucette, A.M.; Jantzen, R.C.
1993-08-30
Mixed wastes at the Rocky Flats Plant (RFP) are subject to regulation by the Resource Conservation and Recovery Act (RCRA). Polymer solidification is being developed as a final treatment technology for several of these mixed wastes, including nitrate salts. Encapsulation nitrate salts with low density polyethylene (LDPE) has been the preliminary focus of the RFP polymer solidification effort. Literature reviews, industry surveys, and lab-scale and pilot-scale tests have been conducted to evaluate several options for encapsulating nitrate salts with LDPE. Most of the effort has focused on identifying compatible drying and extrusion technologies. Other processing options, specifically meltration and non-heatedmore » compounding machines, were also investigated. The best approach appears to be pretreatment of the nitrate salt waste brine in either a vertical or horizontal thin film evaporator followed by compounding of the dried waste with LDPE in an intermeshing, co-rotating, twin-screw extruder. Additional pilot-scale tests planned for the fall of 1993 should further support this recommendation. Preliminary evaluation work indicates that meltration is not possible at atmospheric pressure with the LDPE (Chevron PE-1409) provided by RFP. However, meltration should be possible at atmospheric pressure using another LDPE formulation with altered physical and rheological properties: Lower molecular weight and lower viscosity (Epoline C-15). Contract modifications are now in process to allow a follow-on pilot scale demonstration. Questions regarding changed safety and physical properties of the resultant LDPE waste form due to use of the Epoline C-15 will be addressed. No additional work with non-heated mixer compounder machines is planned at this time.« less
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MuPeXI: prediction of neo-epitopes from tumor sequencing data.
Bjerregaard, Anne-Mette; Nielsen, Morten; Hadrup, Sine Reker; Szallasi, Zoltan; Eklund, Aron Charles
2017-09-01
Personalization of immunotherapies such as cancer vaccines and adoptive T cell therapy depends on identification of patient-specific neo-epitopes that can be specifically targeted. MuPeXI, the mutant peptide extractor and informer, is a program to identify tumor-specific peptides and assess their potential to be neo-epitopes. The program input is a file with somatic mutation calls, a list of HLA types, and optionally a gene expression profile. The output is a table with all tumor-specific peptides derived from nucleotide substitutions, insertions, and deletions, along with comprehensive annotation, including HLA binding and similarity to normal peptides. The peptides are sorted according to a priority score which is intended to roughly predict immunogenicity. We applied MuPeXI to three tumors for which predicted MHC-binding peptides had been screened for T cell reactivity, and found that MuPeXI was able to prioritize immunogenic peptides with an area under the curve of 0.63. Compared to other available tools, MuPeXI provides more information and is easier to use. MuPeXI is available as stand-alone software and as a web server at http://www.cbs.dtu.dk/services/MuPeXI .
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NASA Astrophysics Data System (ADS)
Kim, Yeji; Chikamatsu, Masayuki; Azumi, Reiko; Saito, Takeshi; Minami, Nobutsugu
2013-02-01
We report that single-walled nanotube (SWNT) films with precisely controlled thicknesses and transmittances can be produced through the doctor-blade method using SWNT-polymer inks. The matrix polymer around SWNTs were successfully removed by either solution curing or photonic curing at room temperature, which are advantageous processes enabling direct film formation on plastic substrates. Sheet resistances as low as 68-240 Ω/sq at T=89-98% were obtained. Furthermore, the SWNT film on poly(ethylene naphthalate) exhibited superior flexibility and stability in a flexure endurance test. The method may open a wide range of opportunities for flexible electrical devices.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Sowińska, Małgorzata, E-mail: malgorzata.sowinska@b-tu.de; Henkel, Karsten; Schmeißer, Dieter
2016-01-15
The process parameters' impact of the plasma-enhanced atomic layer deposition (PE-ALD) method on the oxygen to nitrogen (O/N) ratio in titanium oxynitride (TiO{sub x}N{sub y}) films was studied. Titanium(IV)isopropoxide in combination with NH{sub 3} plasma and tetrakis(dimethylamino)titanium by applying N{sub 2} plasma processes were investigated. Samples were characterized by the in situ spectroscopic ellipsometry, x-ray photoelectron spectroscopy, and electrical characterization (current–voltage: I-V and capacitance–voltage: C-V) methods. The O/N ratio in the TiO{sub x}N{sub y} films is found to be very sensitive for their electric properties such as conductivity, dielectric breakdown, and permittivity. Our results indicate that these PE-ALD film propertiesmore » can be tuned, via the O/N ratio, by the selection of the process parameters and precursor/coreactant combination.« less
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NASA Astrophysics Data System (ADS)
Ahmed, M. H. M.; Ali, N. M.; Salleh, Z. S.; Rahman, A. A.; Harun, S. W.; Manaf, M.; Arof, H.
2015-01-01
A passive, stable and low cost Q-switched Erbium-doped fiber laser (EDFL) is demonstrated using both single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs), which are embedded in polyethylene oxide (PEO) film as a saturable absorber (SA). The film is sandwiched between two FC/PC fiber connectors and integrated into the laser cavity for Q-switching pulse generation operating at wavelength of 1533.6 nm. With SWCNTs, the laser produces a stable pulse train with repetition rate and pulse width ranging from 9.52 to 33.33 kHz and 16.8 to 8.0 μs while varying the 980 nm pump power from 48.5 mW to 100.4 mW. On the other hand, with MWCNTs, the repetition rate and pulse width can be tuned in a wider range of 6.12-33.62 kHz and 9.5- 4.2 μs, respectively as the pump power increases from 37.9 to 120.6 mW. The MWCNTs produce the pulse train at a lower threshold and attain a higher repetition rate compared to the SWCNTs. This is due to thicker carbon nanotubes layer of the MWCNTs which provides more absorption and consequently higher damage threshold. The Q-switched EDFL produces the highest pulse energy of 531 nJ at pump power of 37.9 mW with the use of MWCNTs-PEO SA.
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Fröhlich, Sophie M; Archodoulaki, Vasiliki-Maria; Allmaier, Günter; Marchetti-Deschmann, Martina
2014-10-07
Ultrahigh molecular weight polyethylene (PE-UHMW), a material with high biocompatibility and excellent mechanical properties, is among the most commonly used materials for acetabular cup replacement in artificial joint systems. It is assumed that the interaction with synovial fluid in the biocompartment leads to significant changes relevant to material failure. In addition to hyaluronic acid, lipids are particularly relevant for lubrication in an articulating process. This study investigates synovial lipid adsorption on two different PE-UHMW materials (GUR-1050 and vitamin E-doped) in an in vitro model system by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry imaging (MSI). Lipids were identified by high performance thin layer chromatography (HP-TLC) and tandem mass spectrometry (MS/MS) analysis, with an analytical focus on phospholipids and cholesterol, both being species of high importance for lubrication. Scanning electron microscopy (SEM) analysis was applied in the study to correlate molecular information with PE-UHMW material qualities. It is demonstrated that lipid adsorption preferentially occurs in rough or oxidized polymer regions. Polymer modifications were colocalized with adsorbed lipids and found with high density in regions identified by SEM. Explanted, the in vivo polymer material showed comparable and even more obvious polymer damage and lipid adsorption when compared with the static in vitro model. A three-dimensional reconstruction of MSI data from consecutive PE-UHMW slices reveals detailed information about the diffusion process of lipids in the acetabular cup and provides, for the first time, a promising starting point for future studies correlating molecular information with commonly used techniques for material analysis (e.g., Fourier-transform infrared spectroscopy, nanoindentation).
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Joyce, Abigail S; Pirogovsky, Mallory S; Adams, Rachel G; Lao, Wenjian; Tsukada, David; Cash, Curtis L; Haw, James F; Maruya, Keith A
2015-05-01
Low-density polyethylene (PE) passive samplers containing performance reference compounds (PRCs) were deployed at multiple depths in two urban coastal marine locations to estimate dissolved concentrations of hydrophobic organic contaminants (HOCs), including dichlorodiphenyltrichloroethane (DDT) and its metabolites, polychlorinated biphenyl (PCB) congeners, and polybrominated flame retardants. PE samplers pre-loaded with PRCs were deployed at the surface, mid-column, and near bottom at sites representing the nearshore continental shelf off southern California (Santa Monica Bay, USA) and a mega commercial port (Los Angeles Harbor). After correcting for fractional equilibration using PRCs, concentrations ranged up to 100 pg L(-1) for PCBs and polybrominated diphenyl ethers (PBDEs), 500 pg L(-1) for DDMU and 300 pg L(-1) for DDNU, and to 1000 pg L(-1) for p,p'-DDE. Seawater concentrations of DDTs and PCBs increased with depth, suggesting that bed sediments serve as the source of water column HOCs in Santa Monica Bay. In contrast, no discernable pattern between surface and near-bottom concentrations in Los Angeles Harbor was observed, which were also several-fold lower (DDTs: 45-300 pg L(-1), PCBs: 5-50 pg L(-1)) than those in Santa Monica Bay (DDTs: 2-1100 pg L(-1), PCBs: 2-250 pg L(-1)). Accumulation by mussels co-deployed with the PE samplers at select sites was strongly correlated with PE-estimated seawater concentrations, providing further evidence that these samplers are a viable alternative for monitoring of HOC exposure. Fractional equilibration observed with the PRCs increased with decreasing PRC molar volume indicating the importance of target compound physicochemical properties when estimating water column concentrations using passive samplers in situ. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Global Gridded Emission Inventories of Pentabrominated Diphenyl Ether (PeBDE)
NASA Astrophysics Data System (ADS)
Li, Yi-Fan; Tian, Chongguo; Yang, Meng; Jia, Hongliang; Ma, Jianmin; Li, Dacheng
2010-05-01
Polybrominated diphenyl ethers (PBDEs) are flame retardants widely used in many everyday products such as cars, furniture, textiles, and other electronic equipment. The commercial PBDEs have three major technical mixtures: penta-(PeBDE), octa-(OBDE) and decabromodiphenyl ethers (DeBDE). PeBDE is a mixture of several BDE congeners, such as BDE-47, -99, and -100, and has been included as a new member of persistent organic pollutants (POPs) under the 2009 Stockholm Convention. In order to produce gridded emission inventories of PeBDE on a global scale, information of production, consumption, emission, and physiochemical properties of PeBDE have been searched for published papers, government reports, and internet publications. A methodology to estimate the emissions of PeBDE has been developed and global gridded emission inventories of 2 major congener in PeBDE mixture, BDE-47 and -99, on a 1 degree by 1degree latitude/longitude resolution for 2005 have been compiled. Using these emission inventories as input data, the Canadian Model for Environmental Transport of Organochlorine Pesticides (CanMETOP) model was used to simulate the transport of these chemicals and their concentrations in air were calculated for the year of 2005. The modeled air concentration of BDE-47 and -99 were compared with the monitoring air concentrations of these two congeners in the same year obtained from renowned international/national monitoring programs, such as Global Atmospheric Passive Sampling (GAPS), the Integrated Atmospheric Deposition Network (IADN), and the Chinese POPs Soil and Air Monitoring Program (SAMP), and significant correlations between the modeled results and the monitoring data were found, indicating the high quality of the produced emission inventories of BDE-47 and -99. Keywords: Pentabrominated Diphenyl Ether (PeBDE), Emission Inventories, Global, Model
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Enhanced antioxidant activity of polyolefin films integrated with grape tannins.
Olejar, Kenneth J; Ray, Sudip; Kilmartin, Paul A
2016-06-01
A natural antioxidant derived from an agro-waste of the wine industry, grape tannin, was incorporated by melt blending into three different polyolefins (high-density polyethylene, linear low-density polyethylene and polypropylene) to introduce antioxidant functionality. Significant antioxidant activity was observed at 1% tannin inclusion in all polymer blends. The antioxidant activity was observed to increase steadily with a greater concentration of grape tannins, the highest increases being seen with polypropylene. The mechanical and thermal properties of the polymer films following antioxidant incorporation were minimally altered with up to 3% grape tannins. All of the polyolefin-grape tannin films successfully passed the leachability test following USP661 standard protocol. Superior antioxidant activity was established in polyolefin thin films by utilization of a bulk grape extract obtained from winery waste. Significant increases in antioxidant activity were seen with 1% extract inclusion. This not only demonstrates the potential for food packaging applications of the polyolefin blends, but also valorizes the agro-waste. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.
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Jung, Yen-Sook; Hwang, Kyeongil; Heo, Youn-Jung; Kim, Jueng-Eun; Lee, Donmin; Lee, Cheol-Ho; Joh, Han-Ik; Yeo, Jun-Seok; Kim, Dong-Yu
2017-08-23
Despite the potential of roll-to-roll processing for the fabrication of perovskite films, the realization of highly efficient and reproducible perovskite solar cells (PeSCs) through continuous coating techniques and low-temperature processing is still challenging. Here, we demonstrate that efficient and reliable CH 3 NH 3 PbI 3 (MAPbI 3 ) films fabricated by a printing process can be achieved through synergetic effects of binary processing additives, N-cyclohexyl-2-pyrrolidone (CHP) and dimethyl sulfoxide (DMSO). Notably, these perovskite films are deposited from premixed perovskite solutions for facile one-step processing under a room-temperature and ambient atmosphere. The CHP molecules result in the uniform and homogeneous perovskite films even in the one-step slot-die system, which originate from the high boiling point and low vapor pressure of CHP. Meanwhile, the DMSO molecules facilitate the growth of perovskite grains by forming intermediate states with the perovskite precursor molecules. Consequently, fully printed PeSC based on the binary additive system exhibits a high PCE of 12.56% with a high reproducibility.
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Abiotic degradation of plastic films
NASA Astrophysics Data System (ADS)
Ángeles-López, Y. G.; Gutiérrez-Mayen, A. M.; Velasco-Pérez, M.; Beltrán-Villavicencio, M.; Vázquez-Morillas, A.; Cano-Blanco, M.
2017-01-01
Degradable plastics have been promoted as an option to mitigate the environmental impacts of plastic waste. However, there is no certainty about its degradability under different environmental conditions. The effect of accelerated weathering (AW), natural weathering (NW) and thermal oxidation (TO) on different plastics (high density polyethylene, HDPE; oxodegradable high density polyethylene, HDPE-oxo; compostable plastic, Ecovio ® metalized polypropylene, PP; and oxodegradable metalized polypropylene, PP-oxo) was studied. Plastics films were exposed to AW per 110 hours; to NW per 90 days; and to TO per 30 days. Plastic films exposed to AW and NW showed a general loss on mechanical properties. The highest reduction in elongation at break on AW occurred to HDPE-oxo (from 400.4% to 20.9%) and was higher than 90% for HDPE, HDPE-oxo, Ecovio ® and PP-oxo in NW. No substantial evidence of degradation was found on plastics exposed to TO. Oxo-plastics showed higher degradation rates than their conventional counterparts, and the compostable plastic was resistant to degradation in the studied abiotic conditions. This study shows that degradation of plastics in real life conditions will vary depending in both, their composition and the environment.
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The effect of bearing type on the outcome of total hip arthroplasty.
Peters, Rinne M; Van Steenbergen, Liza N; Stevens, Martin; Rijk, Paul C; Bulstra, Sjoerd K; Zijlstra, Wierd P
2018-04-01
Background and purpose - Alternative bearing surfaces such as ceramics and highly crosslinked polyethylene (HXLPE) were developed in order to further improve implant performance of total hip arthroplasties (THAs). Whether these alternative bearing surfaces result in increased longevity is subject to debate. Patients and methods - Using the Dutch Arthroplasty Register (LROI), we identified all patients with a primary, non-metal-on-metal THA implanted in the Netherlands in the period 2007-2016 (n = 209,912). Cumulative incidence of revision was calculated to determine differences in survivorship of THAs according to bearing type: metal-on-polyethylene (MoPE), metal-on-HXLPE (MoHXLPE), ceramic-on-polyethylene (CoPE), ceramic-on-HXLPE (CoHXLPE), ceramic-on-ceramic (CoC), and oxidized-zirconium-on-(HXL)polyethylene (Ox(HXL)PE). Multivariable Cox proportional hazard regression ratios (HRs) were used for comparisons. Results - After adjustment for confounders, CoHXLPE, CoC, and Ox(HXL)PE resulted in a statistically significantly lower risk of revision compared with MoPE after 9 years follow-up (HR =0.8-0.9 respectively, compared with HR =1.0). For small (22-28 mm) femoral head THAs, lower revision rates were found for CoPE and CoHXLPE (HR =0.9). In the 36 mm femoral head subgroup, CoC-bearing THAs had a lower HR compared with MoHXLPE (HR =0.7 versus 1.0). Crude revision rates in young patients (< 60 years) for CoHXLPE, CoC, and Ox(HXL)PE (HR =0.7) were lower than MoPE (HR =1.0). However, after adjustment for case mix and confounders these differences were not statistically significant. Interpretation - We found a mid-term lower risk of revision for CoHXLPE, CoC, and Ox(HXL)PE bearings compared with traditional MoPE-bearing surfaces.
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Thin film GaP for solar cell application
NASA Astrophysics Data System (ADS)
Morozov, I. A.; Gudovskikh, A. S.; Kudryashov, D. A.; Nikitina, E. V.; Kleider, J.-P.; Myasoedov, A. V.; Levitskiy, V.
2016-08-01
A new approach to the silicon based heterostructures technology consisting of the growth of III-V compounds (GaP) on a silicon substrate by low-temperature plasma enhanced atomic layer deposition (PE-ALD) is proposed. The basic idea of the method is to use a time modulation of the growth process, i.e. time separated stages of atoms or precursors transport to the growing surface, migration over the surface, and crystal lattice relaxation for each monolayer. The GaP layers were grown on Si substrates by PE-ALD at 350°C with phosphine (PH3) and trimethylgallium (TMG) as sources of III and V atoms. Scanning and transmission electron microscopy demonstrate that the grown GaP films have homogeneous amorphous structure, smooth surface and a sharp GaP/Si interface. The GaP/Si heterostructures obtained by PE-ALD compare favourably to that conventionally grown by molecular beam epitaxy (MBE). Indeed, spectroscopic ellipsometry measurements indicate similar interband optical absorption while photoluminescence measurements indicate higher charge carrier effective lifetime. The better passivation properties of GaP layers grown by PE-ALD demonstrate a potential of this technology for new silicon based photovoltaic heterostructure
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NASA Astrophysics Data System (ADS)
Kim, Hwa-Min; Lee, Chang Hyun; Shon, Sun Young; Kim, Bong Hwan
2017-11-01
Aluminum-doped zinc oxide (AZO) films were fabricated on various substrates, such as glass, polyethylene naphthalate (PEN), and polyethylene terephthalate (PET), at room temperature using a facing target sputtering (FTS) system with hetero ZnO and Al2O3 targets, and their electrical and optical properties were investigated. The AZO film on glass exhibited compressive stress while the films on the plastic substrates showed tensile stress. These stresses negatively affected the crystalline quality of the AZO films, and it is suggested that the poor crystalline quality of the films may be related to the neutral Al-based defect complexes formed in the films; these complexes act as neutral impurity scattering centers. AZO films with good optoelectronic properties could be formed on the glass and plastic substrates by the FTS technique using the hetero targets. The AZO films deposited on the glass, PEN, and PET substrates showed very low resistivities, of 5.0 × 10-4 Ω cm, 7.0 × 10-4 Ω cm, and 7.4 × 10-4 Ω cm, respectively. Further, the figure merit of the AZO film formed on the PEN substrate in the visible range (400-700 nm) was significantly higher than that of the AZO film on PET and similar to that of the AZO film on glass. Finally, the average transmittances of the films in the visible range (400-700 nm) were 83.16% (on glass), 76.3% (on PEN), and 78.16% (on PET).
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Morag, Ido; Luria, Gil
2018-04-01
Most studies concerned with participative ergonomic (PE) interventions, focus on organizational rather than group level analysis. By implementing an intervention at a manufacturing plant, the current study, utilizing advanced information systems, measured the effect of line-supervisor leadership on employee exposure to risks. The study evaluated which PE dimensions (i.e., extent of workforce involvement, diversity of reporter role types and scope of analysis) are related to such exposure at the group level. The data for the study was extracted from two separate computerized systems (workforce medical records of 791 employees and an intranet reporting system) during a two-year period. While the results did not confirm the effect of line-supervisor leadership on subordinates' exposure to risks, they did demonstrate relationships between PE dimensions and the employees' exposure to risks. The results support the suggested level of analysis and demonstrate that group-based analysis facilitates the assimilation of preventive interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Navarro, Simón; Bermejo, Salvador; Vela, Nuria; Hernández, Joaquín
2009-07-22
This paper reports the use of solar heating by polyethylene mulching for decontamination of a silty clay-loam soil polluted with herbicides. Soil solarization, a natural and hydrothermal method commonly used for disinfesting soils, was tested during the summer season on a Hipercalcic Calcisol located in Murcia (southeast Spain) for dissipation of s-triazine (simazine and terbuthylazine) and phenylurea (isoproturon and methabenzthiazuron) herbicides using low-density (LD) and high-density (HD) polyethylene (PE) film as a cover. A well-established influence of the film was observed on the dissipation of all herbicides from the soil, although the density (0.92-0.95 g/cm(3)) of the film used (LDPE and HDPE) was not significant in terms of the rate of loss. In all cases, a quick depletion during the first 2 weeks was observed, mainly for terbuthylazine. The first-order model satisfactorily explained the dissipation process, but the Hoerl and biexponential equations were more appropriate, mainly for simazine, isoproturon, and methabenzthiazuron. In all cases, herbicides disappeared at faster rates in solarized soils (DT(50) = 4-29 days) than in nonmulched soils (DT(50) = 11-35 days), especially for terbuthylazine and isoproturon.
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Linker-based GnRH-PE chimeric proteins inhibit cancer growth in nude mice.
Ben-Yehudah, A; Yarkoni, S; Nechushtan, A; Belostotsky, R; Lorberboum-Galski, H
1999-04-01
Since the number of cancer-related deaths has not decreased in recent years, major efforts are being made to find new drugs for cancer treatment. In this report we introduce the gonadotropin releasing hormone-Pseudomonas exotoxin (GnRH-PE) based chimeric proteins L-GnRH-PE66 and L-GnRH-PE40. These proteins are composed of a GnRH moiety attached to modified forms of Pseudomonas exotoxin via a polylinker (gly4ser)2. The chimeric proteins L-GnRH-PE66 and L-GnRH-PE40 have the ability to target and kill adenocarcinoma cell lines in vitro, whereas non-adenocarcinoma cell lines are not affected. We demonstrate that L-GnRH-PE66 and L-GnRH-PE40 efficiently inhibit cancer growth. Nude mice were injected subcutaneously with the SW-48 adenocarcinoma cell line to produce xenograft tumours. When the tumours were established and visible, the animals were injected with chimeric proteins for 10 days. At the end of this period, a reduction of up to 3-fold in tumor size was obtained in the treated mice, as compared with the control group, which received equivalent amounts of GnRH; the difference was even greater 13 days after termination of treatment. Thus, the chimeric proteins L-GnRH-PE66 and L-GnRH-PE40 are promising candidates for treatment of a variety of adenocarcinomas and their use in humans should be considered.
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NASA Astrophysics Data System (ADS)
Cui, Zhiwei; Tian, Yi-Xing; Yue, Wen; Yang, Lei; Li, Qunyang
2016-06-01
Artificial total hip arthroplasty (THA) is one of the most effective orthopaedic surgeries that has been used for decades. However, wear of the articulating surfaces is one of the key failure causes limiting the lifetime of total hip implant. In this paper, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were employed to explore the composition and formation mechanism of the tribo-layer on the articulating surfaces of metal-on-polyethylene (MoPE) implants retrieved from patients. Results showed that, in contrast to conventional understanding, the attached tribo-layer contained not only denatured proteins but also a fraction of polymer particles. The formation of the tribo-layer was believed to relate to lubrication regime, which was supposed to be largely affected by the nature of the ultra-high-molecule-weight-polyethylene (UHMWPE). Wear and formation of tribo-layer could be minimized in elasto-hydrodynamic lubrication (EHL) regime when the UHMWPE was less stiff and have a morphology containing micro-pits; whereas the wear was more severe and tribo-layer formed in boundary lubrication. Our results and analyses suggest that enhancing interface lubrication may be more effective on reducing wear than increasing the hardness of material. This finding may shed light on the design strategy of artificial hip joints.
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Canellas, Elena; Vera, Paula; Nerín, Cristina
2017-10-01
The suitability of an acrylic adhesive used on food packaging was studied. Six potential migrants were identified using GC-MS and UPLC-QTOF. Five compounds were intentionally added (2-butoxyethanol and 2,4,7,9-tetramethyl-5-decyne-4,7-diol 10 (TMDD) and TMDD ethoxylates). One of the compounds identified as 2-(12-(methacryloyloxy) dodecyl)malonic acid was a non -intentionally added substance (NIAS), which could be a methyl metacrylate derivative. A migration study from multilayers containing paper-adhesive-film was carried out. The films used were polyethylene (PE), polypropylene, polyethylene terephthalate, polylactic acid (PLA) and Ecovio F2223®, which is a mixture of biodegradable polyester with PLA. All the non-volatile compounds, including the identified NIAS, migrated into the dry food simulant Tenax ®. Five surfactants based on TMDD were found to migrate from all laminates into Tenax at levels from 0.05 to 0.6 mg kg -1 . The results showed that the lowest migration (0.01 mg kg -1 for 2-(12-(methacryloyloxy)dodecyl)malonic acid to 0.07 for TMDD mg kg -1 ) occurred when the compounds passed through PLA, demonstrating its functional barrier properties to these compounds. In contrast, PE showed the worst barrier properties to these compounds. To evaluate the migration results, the threshold of toxicological concern strategy was applied. The migration values of the surfactant identified were above 0.09 mg kg -1 . Thus, it was decided to remove this surfactant from the formulation.
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Tran, H S; Malli, D; Chrzanowski, F A; Puc, M M; Matthews, M S; Hewitt, C W
1999-05-15
Dermal application of immunosuppressants can be an effective means of achieving site-specific immunosuppression (SITE) on skin allografts in burn wound management and in the treatment of various immune skin disorders. We have previously reported success with topical cyclosporine A (tCsA) in the treatment of skin allograft rejection in rats. Using a new tCsA formulation with a penetration enhancer (PE), polyethylene glycol-8 (PEG-8) glyceryl caprylate/caprate (Labrasol, Gattefossé, St. Priest, France), in a trinary drug delivery system, we hypothesized that we would induce SITE and significantly delay rejection of dual skin allografts in rats. Dual rat skin allografts from Lewis x Brown-Norway (LBN) donors were grafted to Lewis (Lew) recipients. Experimental animals (EXP, n = 7) received a 10-day course of systemic cyclosporine (sCsA, 8 mg/kg/day) followed by topical application. One of the two allografts on each experimental animal received tCsA/PE application (5 mg/kg/day) until sacrifice (tCsA/PE-treated). The other allograft received vehicle only (vehicle-treated). Allogeneic controls (ALLO-CON, n = 9) received no sCsA or tCsA. First signs of rejection were determined based on the initial observation of erythema, hair loss, flakiness, and/or scabs. The mean time to rejection for ALLO-CON allografts was 6.3 +/- 0.7 days (t test, P = 0.0013); for vehicle-treated allografts, 12.3 +/- 3.8 days (paired t test, P = 0.0146); and for tCsA/PE-treated allografts, 25.6 +/- 5.4 days. The disparity of days to rejection between dual allografts in the ALLO-CON group was 0.0 +/- 0.0 day and that between the tCsA/PE- and vehicle-treated dual allografts was 13.3 +/- 3.9 days (t test, P = 0.0016). A new formulation of tCsA in a trinary drug delivery system is successful at delaying the onset of rejection in dual skin allografts in rats by SITE, and PEG-8 glyceryl caprylate/caprate may represent a potentially effective transdermal penetration enhancer. Copyright 1999 Academic
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Polyethylene wear debris in modular acetabular prostheses.
Chen, P C; Mead, E H; Pinto, J G; Colwell, C W
1995-08-01
The longevity of total hip arthroplasty has brought forth the recognition of aseptic loosening of prosthetic components as the leading cause of implant failure. Modularity of implants, although a significant improvement in versatility, may increase debris formation, a recognized cause of implant failure. This study was designed to measure the relative motion, and to assess the polyethylene wear debris production at the interface between the metal acetabular shell and the back side of the polyethylene liner, in modular hip prostheses. Five models from 4 manufacturers with different locking mechanisms and acetabular shell surface treatments were tested under long-term simultaneous sinusoidal and static loading (10(7) cycles at 3 Hz with +/- 2.5 Nmeter and 220 N static load). Results showed that there were marked differences in the security of the acetabular shell and polyethylene liner locking mechanism, wear pattern, damage sites, and amount of polyethylene debris on the acetabular shell and polyethylene liner surfaces. The range of polyethylene liner motion observed among the 5 models during 1 cycle of testing varied from an average of 0.96 degrees to movement too small to be detected by the test machines. Image and scanning electron microscopy analysis showed different wear patterns and a wide range in the average polyethylene liner surface wear area (0.26 cm2-4.61 cm2). In general, a stable locking mechanism and a smooth acetabular shell surface are essential in minimizing polyethylene liner wear and polyethylene debris production.
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Impact of protein domains on PE_PGRS30 polar localization in Mycobacteria.
De Maio, Flavio; Maulucci, Giuseppe; Minerva, Mariachiara; Anoosheh, Saber; Palucci, Ivana; Iantomasi, Raffaella; Palmieri, Valentina; Camassa, Serena; Sali, Michela; Sanguinetti, Maurizio; Bitter, Wilbert; Manganelli, Riccardo; De Spirito, Marco; Delogu, Giovanni
2014-01-01
PE_PGRS proteins are unique to the Mycobacterium tuberculosis complex and a number of other pathogenic mycobacteria. PE_PGRS30, which is required for the full virulence of M. tuberculosis (Mtb), has three main domains, i.e. an N-terminal PE domain, repetitive PGRS domain and the unique C-terminal domain. To investigate the role of these domains, we expressed a GFP-tagged PE_PGRS30 protein and a series of its functional deletion mutants in different mycobacterial species (Mtb, Mycobacterium bovis BCG and Mycobacterium smegmatis) and analysed protein localization by confocal microscopy. We show that PE_PGRS30 localizes at the mycobacterial cell poles in Mtb and M. bovis BCG but not in M. smegmatis and that the PGRS domain of the protein strongly contributes to protein cellular localization in Mtb. Immunofluorescence studies further showed that the unique C-terminal domain of PE_PGRS30 is not available on the surface, except when the PGRS domain is missing. Immunoblot demonstrated that the PGRS domain is required to maintain the protein strongly associated with the non-soluble cellular fraction. These results suggest that the repetitive GGA-GGN repeats of the PGRS domain contain specific sequences that contribute to protein cellular localization and that polar localization might be a key step in the PE_PGRS30-dependent virulence mechanism.
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Taber, Daniel R; Chriqui, Jamie F; Perna, Frank M; Powell, Lisa M; Slater, Sandy J; Chaloupka, Frank J
2013-11-01
To determine if state physical education (PE) laws are associated with student physical education attendance and physical activity (PA), and whether physical education and competitive food laws, in conjunction, are associated with lower BMI change. State laws regarding physical education time requirements and competitive foods in 2003 and 2006 were classified as strong, weak, or none, based on codified law ratings obtained from the Classification of Laws Associated with School Students. Laws were linked to student data on PE attendance and physical activity (8th grade, Spring 2007) and BMI change (5th-8th grade, 2004-2007), obtained from the Early Childhood Longitudinal Study (n=5510 students in 40 states). Girls reported 0.31 more days of activity (95% CI: 0.02, 0.61) and were more likely to attend physical education ≥ 3 days/week (74.1% versus 52.1%, difference=22.0, 95% CI: 2.1, 42.0) if they resided in states with strong physical education laws compared to no physical education laws. Weak physical education laws had modest associations with PE and activity, and there was no evidence that weak laws reduce BMI gain regardless of competitive food laws. Strong physical education laws with specific time requirements may increase physical education attendance and activity in girls. There is insufficient evidence that physical education laws reduce student weight gain. © 2013.
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ERIC Educational Resources Information Center
Backman, Erik; Pearson, Phil
2016-01-01
The question of what knowledge a student of Physical Education (PE) needs to develop during PE teacher education (PETE) was recently discussed. One form of knowledge is the movement practices that students must meet during their education. Given the limited time, a delicate matter is whether to prioritize movement knowledge and consider it as…
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Optimization of esterification of oleic acid and trimethylolpropane (TMP) and pentaerythritol (PE)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mahmud, Hamizah Ammarah; Salimon, Jumat
Vegetable oil (VO) is the most potential alternative to replace mineral oil for lubricant due to better lubricating properties and great physicochemical properties. Chemical modification has to be done to overcome low temperature performance and low oxidation instability due to the presence of β-hydrogen atoms of glycerol molecule. The optimization of esterification of oleic acid and polyhydric alcohol with sulfuric acid catalyst was carried out to find the optimum conditions with the highest yield. Reeaction variables such as; molar ratio, temperature, duration and catalyst concentration. Two types of polyhydric alcohol have been used; TMP and PE. The optimum results showedmore » oleic acid successfully converted 91.2% ester TMP and 92.7% ester PE at duration: 5 hours (Ester TMP), 6 hours (Ester PE); temperature: 150°C (ester TMP), 180°C (Ester PE); catalyst concentration: 1.5% (w/w); and mol ratio: 3.9:1 (ester TMP), 4.9:1 (ester PE). From the data obtained, mole ratio showed most influenced factors to the increasing yields of ester conversions.. The TMP/PE ester was confirmed using gas chromatography (GC-FID), Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR)« less
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Kim, Eun-Ah; Luthy, Richard G
2011-11-01
This study investigated the role of dissolved organic matter on mercury partitioning between a hydrophobic surface (polyethylene, PE) and a reduced sulfur-rich surface (polysulfide rubber, PSR). Comparative sorption studies employed polyethylene and polyethylene coated with PSR for reactions with DOM-bound mercuric ions. These studies revealed that PSR enhanced the Hg-DOM removal from water when DOM was Suwannee River natural organic matter (NOM), fulvic acid (FA), or humic acid (HA), while the same amount of 1,3-propanedithiol-bound mercuric ion was removed by both PE and PSR-PE. The differences for Hg-DOM removal efficiencies between PE and PSR-PE varied depending on which DOM was bound to mercuric ion as suggested by the PE/water and PSR-PE/water partition coefficients for mercury. The surface concentrations of mercury on PE and PSR-PE with the same DOM measured by x-ray photoelectron spectroscopy were similar, which indicated the comparable amounts of immobilized mercury on PE and PSR-PE being exposed to the aqueous phase. With these observations, two major pathways for the immobilization reactions between PSR-PE and Hg-DOM were examined: 1) adsorption of Hg-DOM on PE by hydrophobic interactions between DOM and PE, and 2) addition reaction of Hg-DOM onto PSR by a complexation reaction between Hg and PSR. The percent contribution of each pathway was derived from a mass balance and the ratios among aqueous mercury, PE-bound Hg-DOM, and PSR-bound Hg-DOM concentrations. The results indicate strong binding of mercuric ion with both dissolved organic matter and PSR polymer. The FT-IR examination of Hg-preloaded-PSR-PEs after the reaction with DOM corroborated a strong interaction between mercuric ion and 1,3-propanedithiol compared to Hg-HA, Hg-FA, or Hg-NOM interactions. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Kim, Eun-Ah
2011-01-01
This study investigated the role of dissolved organic matter on mercury partitioning between a hydrophobic surface (polyethylene, PE) and a reduced sulfur-rich surface (polysulfide rubber, PSR). Comparative sorption studies employed polyethylene and polyethylene coated with PSR for reactions with DOM-bound mercuric ions. These studies revealed that PSR enhanced the Hg-DOM removal from water when DOM was Suwannee River natural organic matter (NOM), fulvic acid (FA), or humic acid (HA), while the same amount of 1,3-propanedithiol-bound mercuric ion was removed by both PE and PSR-PE. The differences for Hg-DOM removal efficiencies between PE and PSR-PE varied depending on which DOM was bound to mercuric ion as suggested by the PE/water and PSR-PE/water partition coefficients for mercury. The surface concentrations of mercury on PE and PSR-PE with the same DOM measured by x-ray – photoelectron spectroscopy were similar, which indicated the comparable amounts of immobilized mercury on PE and PSR-PE being exposed to the aqueous phase. With these observations, two major pathways for the immobilization reactions between PSR-PE and Hg- DOM were examined: 1) adsorption of Hg-DOM on PE by hydrophobic interactions between DOM and PE, and 2) addition reaction of Hg-DOM onto PSR by a complexation reaction between Hg and PSR. The percent contribution of each pathway was derived from a mass balance and the ratios among aqueous mercury, PE-bound Hg-DOM, and PSR-bound Hg-DOM concentrations. The results indicate strong binding of mercuric ion with both dissolved organic matter and PSR polymer. The FT-IR examination of Hg-preloaded-PSR-PEs after the reaction with DOM corroborated a strong interaction between mercuric ion and 1,3-propanedithiol compared to Hg-HA, Hg-FA, or Hg-NOM interactions. PMID:21872900
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Novel generation of liquid crystalline photo-actuators based on stretched porous polyethylene films.
Ryabchun, Alexander; Bobrovsky, Alexey; Stumpe, Joachim; Shibaev, Valery
2012-06-14
The preparation of photo-actuators based on stretched porous polyethylene and an azobenzene-containing liquid crystalline polymer network is reported for the first time. It is revealed that this kind of photo-actuator possesses the following advantages: the lack of a need for using aligning coatings and cells preparation, high deformation of the actuator and its complete reversibility, good mechanical properties, and relatively low cost of fabrication. In addition some kinetic and thermodynamic features of the bending and unbending processes have been studied. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Gao, Jie; Kou, Geng; Wang, Hao; Chen, Huaiwen; Li, Bohua; Lu, Ying; Zhang, Dapeng; Wang, Shuhui; Hou, Sheng; Qian, Weizhu; Dai, Jianxin; Zhao, Jian; Zhong, Yanqiang; Guo, Yajun
2009-05-01
The clinical use of Pseudomonas exotoxin A (PE)-based immunotoxins is limited by the toxicity and immunogenicity of PE. To overcome the limitations, we have developed PE38KDEL-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles conjugated with Fab' fragments of a humanized anti-HER2 monoclonal antibody (rhuMAbHER2). The PE38KDEL-loaded nanoparticles-anti-HER2 Fab' bioconjugates (PE-NP-HER) were constructed modularly with Fab' fragments of rhuMAbHER2 covalently linked to PLGA nanoparticles containing PE38KDEL. Compared with nontargeted nanoparticles that lack anti-HER2 Fab', PE-NP-HER specifically bound to and were sequentially internalized into HER2 overexpressing breast cancer cells, which result in significant cytotoxicity in vitro. In HER2 overexpressing tumor xenograft model system, administration of PE-NP-HER showed a superior efficacy in inhibiting tumor growth compared with PE-HER referring to PE38KDEL conjugated directly to rhuMAbHER2. Moreover, PE-NP-HER was well tolerated in mice with a higher LD(50) (LD(50) of 6.86 +/- 0.47 mg/kg vs. 2.21 +/- 0.32 mg/kg for PE-NP-HER vs. PE-HER (mean +/- SD); n = 3), and had no influence on the plasma level of plasma alanine aminotransferase (ALT) of animals when injected at a dose of 1 mg/kg where PE-HER caused significant increase of serum ALT in the treated mice. Notably, PE-NP-HER was of low immunogenicity in development of anti-PE38KDEL neutralizing antibodies and was less susceptible to inactivation by anti-PE38KDEL antibodies compared with PE-HER. This novel bioconjugate, PE-NP-HER, may represent a useful strategy for cancer treatment.
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Biodegradation of polyethylene by the thermophilic bacterium Brevibacillus borstelensis.
Hadad, D; Geresh, S; Sivan, A
2005-01-01
To select a polyethylene-degrading micro-organism and to study the factors affecting its biodegrading activity. A thermophilic bacterium Brevibaccillus borstelensis strain 707 (isolated from soil) utilized branched low-density polyethylene as the sole carbon source and degraded it. Incubation of polyethylene with B. borstelensis (30 days, 50 degrees C) reduced its gravimetric and molecular weights by 11 and 30% respectively. Brevibaccillus borstelensis also degraded polyethylene in the presence of mannitol. Biodegradation of u.v. photo-oxidized polyethylene increased with increasing irradiation time. Fourier Transform Infra-Red (FTIR) analysis of photo-oxidized polyethylene revealed a reduction in carbonyl groups after incubation with the bacteria. This study demonstrates that polyethylene--considered to be inert--can be biodegraded if the right microbial strain is isolated. Enrichment culture methods were effective for isolating a thermophilic bacterium capable of utilizing polyethylene as the sole carbon and energy source. Maximal biodegradation was obtained in combination with photo-oxidation, which showed that carbonyl residues formed by photo-oxidation play a role in biodegradation. Brevibaccillus borstelensis also degraded the CH2 backbone of nonirradiated polyethylene. Biodegradation of polyethylene by a single bacterial strain contributes to our understanding of the process and the factors affecting polyethylene biodegradation.
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Film transfer enabled by nanosheet seed layers on arbitrary sacrificial substrates
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dral, A. P.; Nijland, M.; Koster, G.
An approach for film transfer is demonstrated that makes use of seed layers of nanosheets on arbitrary sacrificial substrates. Epitaxial SrTiO{sub 3}, SrRuO{sub 3}, and BiFeO{sub 3} films were grown on Ca{sub 2}Nb{sub 3}O{sub 10} nanosheet seed layers on phlogopite mica substrates. Cleavage of the mica substrates enabled film transfer to flexible polyethylene terephthalate substrates. Electron backscatter diffraction, X-ray diffraction, and atomic force microscopy confirmed that crystal orientation and film morphology remained intact during transfer. The generic nature of this approach is illustrated by growing films on zinc oxide substrates with a nanosheet seed layer. Film transfer to a flexiblemore » substrate was accomplished via acid etching.« less
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Tensile and fatigue behaviors of printed Ag thin films on flexible substrates
NASA Astrophysics Data System (ADS)
Sim, Gi-Dong; Won, Sejeong; Lee, Soon-Bok
2012-11-01
Flexible electronics using nanoparticle (NP) printing has been highlighted as a key technology enabling eco-friendly, low-cost, and large-area fabrication. For NP-based printing to be used as a successive alternative to photolithography and vacuum deposition, stretchability and long term reliability must be considered. This paper reports the stretchability and fatigue behavior of 100 nm thick NP-based silver thin films printed on polyethylene-terephthalate substrate and compares it to films deposited by electron-beam evaporation. NP-based films show stretchability and fatigue life comparable to evaporated films with intergranular fracture as the dominant failure mechanism.
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Plasma-induced graft-polymerization of polyethylene glycol acrylate on polypropylene substrates
NASA Astrophysics Data System (ADS)
Zanini, S.; Orlandi, M.; Colombo, C.; Grimoldi, E.; Riccardi, C.
2009-08-01
A detailed study of argon plasma-induced graft-polymerization of polyethylene glycol acrylate (PEGA) on polypropylene (PP) substrates (membranes and films) is presented. The process consists of four steps: (a) plasma pre-activation of the PP substrates; (b) immersion in a PEGA solution; (c) argon plasma-induced graft-polymerization; (d) washing and drying of the samples. Influence of the solution and plasma parameters on the process efficiency evaluated in terms of amount of grafted polymer, coverage uniformity and substrates wettability, are investigated. The plasma-induced graft-polymerization of PEGA is then followed by sample weighting, water droplet adsorption time and contact angle measurements, attenuated total reflection infrared spectroscopy (ATR-IR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) analyses. The stability of the obtained thin films was evaluated in water and in phosphate buffer saline (PBS) at 37 °C. Results clearly indicates that plasma-induced graft-polymerization of PEGA is a practical methodology for anti-fouling surface modification of materials.
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Preparation and characterization of collagen/hydroxypropyl methylcellulose (HPMC) blend film.
Ding, Cuicui; Zhang, Min; Li, Guoying
2015-03-30
This study aimed to prepare and characterize the collagen/HPMC blend film (1/1). Thermogravimetric analysis and differential scanning calorimetry were used to investigate the thermal properties of the film. Both thermal decomposition temperature and denaturation temperature of the blend film were higher than those of the collagen film due to the intermolecular hydrogen bonding interaction between collagen and HPMC, which was demonstrated by Fourier transform infrared spectroscopy. Additionally, the morphologies, mechanical properties and hydrophilicity of films were examined. The blend film exhibited a more homogeneous and compact structure compared with that of the collagen film, as observed from scanning electron microscopy and atomic force microscopy. The tensile strength, ultimate elongation and hydrophilicity of the blend film were superior to those of the pure collagen film. Furthermore, the introduction of polyethylene glycol 1500 had almost no influence on the thermal properties of the blend film but obviously improved its stretch-ability and smoothness. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Production and crosslinking of multi-layer tubes (PE & metal) by E-beam
NASA Astrophysics Data System (ADS)
Zyball, Alfred
2000-03-01
Irradiation crosslinking of PE-tubes has been used for heating floors for about 25 years. Such tubes are also used today for drinking water supply. A further development has been the coating of such tubes with Ethylene-Vinyl-Alcohol-Copolymers (EVAL), in order to prevent oxygen diffusion into the water through the PE tube. For about 15 years composite tubes made of PE and aluminum have been available. These tubes are crosslinked with electron beams. The energy of the accelerated electrons must be adjusted for the particular tube configuration, so that the inner PE-layer will be crosslinked. This paper will concern itself with the manufacture and the crosslinking of composite tubes.
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Code of Federal Regulations, 2011 CFR
2011-07-01
... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Boric acid (H3BO3), mixed esters with... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...
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Code of Federal Regulations, 2014 CFR
2014-07-01
... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Boric acid (H3BO3), mixed esters with... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...
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Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO3), mixed esters with... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...
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Code of Federal Regulations, 2013 CFR
2013-07-01
... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Boric acid (H3BO3), mixed esters with... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...
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Code of Federal Regulations, 2012 CFR
2012-07-01
... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Boric acid (H3BO3), mixed esters with... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...
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Attitudes toward and Motivation for PE. Who Collects the Benefits of the Subject?
ERIC Educational Resources Information Center
Säfvenbom, Reidar; Haugen, Tommy; Bulie, Marte
2015-01-01
Background and purpose: Due to attitudinal and motivational aims in the national curriculum, and to lack of research on adolescents' experiences with physical education (PE) in Norway, the purposes of this study were to (1) attain data on attitudes toward PE and self-determined motivation for PE among a representative sample of adolescents (N =…
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In Situ Study of Strain-Dependent Ion Conductivity of Stretchable Polyethylene Oxide Electrolyte
Kelly, Taylor; Ghadi, Bahar Moradi; Berg, Sean; Ardebili, Haleh
2016-01-01
There is a strong need in developing stretchable batteries that can accommodate stretchable or irregularly shaped applications including medical implants, wearable devices and stretchable electronics. Stretchable solid polymer electrolytes are ideal candidates for creating fully stretchable lithium ion batteries mainly due to their mechanical and electrochemical stability, thin-film manufacturability and enhanced safety. However, the characteristics of ion conductivity of polymer electrolytes during tensile deformation are not well understood. Here, we investigate the effects of tensile strain on the ion conductivity of thin-film polyethylene oxide (PEO) through an in situ study. The results of this investigation demonstrate that both in-plane and through-plane ion conductivities of PEO undergo steady and linear growths with respect to the tensile strain. The coefficients of strain-dependent ion conductivity enhancement (CSDICE) for in-plane and through-plane conduction were found to be 28.5 and 27.2, respectively. Tensile stress-strain curves and polarization light microscopy (PLM) of the polymer electrolyte film reveal critical insights on the microstructural transformation of stretched PEO and the potential consequences on ionic conductivity. PMID:26831948
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Validation of a model for the cast-film process
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chambon, F.; Ohlsson, S.; Silagy, D.
1996-12-31
We have developed a model of the cast-film process and compared theoretical predictions against experiments on a pilot line. Three polyethylenes with a markedly different level of melt elasticity were used in this evaluation; namely, a high pressure low density polyethylene, LDPE, and two linear low density polyethylenes, LLDPE-1 and LLDPE-2. The final film dimensions of the LDPE were found to be in good agreement with 1-D viscoelastic stationary predictions. Flow field visualization experiments indicate, however, a 2-D velocity field in the airgap between the extrusion die and the chill roll. Taking this observation into account, evolutions of the freemore » surface of the web along the airgap were recorded with LLDPE-2, our least elastic melt. An excellent agreement is found between these measurements and predictions of neck-in and edge bead with 2-D Newtonian stationary simulations. The time-dependent solution, which is based on a linear stability analysis, allows to identify a zone of draw resonance within the working space of the process, defined by the draw ratio, the Deborah number, and the web aspect ratio. It is predicted that increasing this latter parameter stabilizes the process until an optimum value is reached. Experiments with LLDPE-1 are shown to validate this unique theoretical result, thus allowing to increase the draw ratio by about 75%.« less
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Wong, Dana E; Talbert, Joey N; Goddard, Julie M
2013-06-01
Active packaging is utilized to overcome limitations of traditional processing to enhance the health, safety, economics, and shelf life of foods. Active packaging employs active components to interact with food constituents to give a desired effect. Herein we describe the development of an active package in which lactase is covalently attached to low-density polyethylene (LDPE) for in-package production of lactose-free dairy products. The specific goal of this work is to increase the total protein content loading onto LDPE using layer by layer (LbL) deposition, alternating polyethylenimine, glutaraldehyde (GL), and lactase, to enhance the overall activity of covalently attached lactase. The films were successfully oxidized via ultraviolet light, functionalized with polyethylenimine and glutaraldehyde, and layered with immobilized purified lactase. The total protein content increased with each additional layer of conjugated lactase, the 5-layer sample reaching up to 1.3 μg/cm2 . However, the increase in total protein did not lend to an increase in overall lactase activity. Calculated apparent Km indicated the affinity of immobilized lactase to substrate remains unchanged when compared to free lactase. Calculated apparent turnover numbers (kcat ) showed with each layer of attached lactase, a decrease in substrate turnover was experienced when compared to free lactase; with a decrease from 128.43 to 4.76 s(-1) for a 5-layer conjugation. Our results indicate that while LbL attachment of lactase to LDPE successfully increases total protein mass of the bulk material, the adverse impact in enzyme efficiency may limit the application of LbL immobilization chemistry for bioactive packaging use. © 2013 Institute of Food Technologists®
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Evaluation of films for packaging applications in high pressure processing
NASA Astrophysics Data System (ADS)
Largeteau, A.; Angulo, I.; Coulet, J. P.; Demazeau, G.
2010-03-01
Food treatments implying high pressures used pre-packaging systems; consequently it appeared necessary to validate different packaging films able to be used in such processes. Two different packaging films from AMCOR FLEXIBLES have been evaluated: VIROFLEXAL: BOLSA 80 MICRAS, coextrusion PA/PE (20/60μm) RILTHENE: SEMI 20/60 MICRAS, laminate PA/PE (20/60μm) Three different physico-chemical characterizations have been developed for the evaluation of films behaviour after High Hydrostatic Pressure (HHP): (i) Mechanical properties (tensile strength and sealing strength), (ii) Oxygen permeability, (iii) Migration, through the contact with four food simulating liquids FSLs (water, acetic acid 3%, ethyl alcohol 10%, iso-octane). Two different pressures values (P = 400MPa and 500MPa) have been tested, with a duration of 15 min, at ambient temperature (+20°C) and only one pressure (P = 200MPa) for the experiments at low temperature (T = -20°C) with the same duration (15min). The selection of such values can be justified taking into account that experimental conditions as a temperature close to +20°C and a pressure between 400 and 500MPa are appropriated to inactivate bacteria and different others micro-organisms. Due to the efficiency of the association of hydrostatic pressure processing and low temperature (HHP/LT) [1, 2], the same films have been tested under high pressure processing (200MPa) but at negative temperature (-20°C).
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Ito, Eiichi; Okamoto, Hiroshi; Mochizuki, Atsuko; Ohara, Kuniko; Kato, Maiko; Terashima, Yutaka; Tanaka, Eiichi; Takagi, Kae; Uchiyama, Shinichiro; Iwata, Makoto
2007-01-01
We encountered two cases of RS3PE (remitting seronegative symmetrical synovitis with pitting edema) syndrome accompanied by Parkinson's disease (PD). Although the etiology of RS3PE syndrome is still unknown, several possible associations, such as malignancies and viral infections, have been reported; RS3PE syndrome is thought to be an autoimmune-mediated disorder. The present patients did not have any factors which are reported to be associated with RS3PE. Whether or not the complication of PD and RS3PE syndrome is incidental needs to be further examined, and we discuss here the possible cause of association between PD and RS3PE syndrome, including dopamine agonists one of the anti-PD medications.
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Ferroelectric properties of YMnO3 epitaxial films for ferroelectric-gate field-effect transistors
NASA Astrophysics Data System (ADS)
Ito, Daisuke; Fujimura, Norifumi; Yoshimura, Takeshi; Ito, Taichiro
2003-05-01
Ferroelectric properties of YMnO3 epitaxial films were studied. The ferroelectric properties of epitaxially grown (0001) YMnO3 films on (111)Pt/(0001)sapphire (epi-YMO/Pt) with an excellent crystallinity were compared to (0001)-oriented poly crystalline films on (111)Pt/ZrO2/SiO2/Si. The epi-YMO/Pt had saturated polarization-electric-field (P-E) hysteresis loops, with a remanent polarization (Pr) of 1.7 μC/cm2 and a coercive field (Ec) of 80 kV/cm. The fatigue property showed no degradation up to 1010 measured cycles. These results suggested that the YMnO3 epitaxial films were suitable ferroelectric material for the ferroelectric-gate field-effect transistors. Consequently, epitaxially grown (0001)YMnO3 films on epitaxial Y2O3/Si (epi-YMO/Si) were fabricated. The epi-YMO/Si capacitor had almost equivalent crystallinity compared to epi-YMO/Pt. It was recognized that the epi-YMO/Si capacitor exhibited the ferroelectric type C-V hysteresis loop with the width of the memory window of 4.8 V, which was almost identical to the value of twice coercive voltage of the P-E hysteresis loops of the epi-YMO/Pt. A retention time exceeding 104 s was obtained in the epi-YMO/Si capacitor.
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-10
... Film, Sheet, and Strip From the People's Republic of China: Preliminary Results of Administrative... terephthalate film, sheet, and strip (``PET film'') from the People's Republic of China (``PRC''), covering the...: Scope of Order The products covered by the order are all gauges of raw, pre- treated, or primed PET film...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-26
... Film, Sheet, and Strip From the People's Republic of China: Preliminary Results of Antidumping Duty... terephthalate film, sheet, and strip (``PET film'') from the People's Republic of China (``PRC''). The period of... covered by the order are all gauges of raw, pre- treated, or primed PET film, whether extruded or co...
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Nature of the Paleocene/Eocene (P/E) boundary in Sinai, Egypt
NASA Astrophysics Data System (ADS)
Obaidalla, Nageh A.; Abdel-Maksoud, Nasr A.; Hosny, Atef M.; Mahfouz, Kamel H.
2017-12-01
The P/E boundary is studied at eight stratigraphic sections in Sinai, Egypt, which are nearly distributed in a stratigraphic profile from north to south as follows: Al-Hasanah, Sudr Al-Hitan, Wadi Sudr, Al-Thamad, Abu Qada, Wadi Matulla, Wadi Nukhul and Wadi Feiran. This study includes field, litho- and bio-stratigraphic analyses that enabled to delineate several hiatuses which may be due to the occurrence of tectonic activity that may be related to the echo of the Syrian Arc Orogeny at the P/E boundary. Generally, in Egypt the P/E boundary is marked by the occurrence of distinctive five beds, named by El Dababiya Quarry Member. At Wadi Nukhul, Wadi Matulla and Wadi Feiran sections, El Dababiya Quarry Member is well represented and the P/E boundary is conformable and resembles the GSSP section. Although El Dababiya Quarry Member is represented at Al-Hasanah section, the P/E boundary is marked by the occurrence of a minor hiatus at the end of Paleocene. Moreover, at Al Thamad section, El Dababiya Quarry Member is partially represented. On the other hand, at Sudr Al-Hitan, Wadi Sudr and Abu Qada sections, El Dababiya Quarry Member is completely absent due to a major hiatus.
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Study of oxygen scavenging PET-based films activated by water
NASA Astrophysics Data System (ADS)
Rossi, Gabriella; Scarfato, Paola; Incarnato, Loredana
2016-05-01
In this work an active barrier system consisting of a thin and transparent film based on polyethylene terephthalate (PET) was studied. Dynamic oxygen absorption measurements were performed at different values of relative humidity and temperature, pointing out that humidity is a key factor in activating the oxidation of the polymer sample. Moreover, the thermal and optical properties of the films were investigated and a good correlation was found between the crystallinity increase and the consequent transparency reduction occurring after the oxygen absorption.